diff --git a/.docker/config/Dockerfile b/.docker/config/Dockerfile
index cb2d05c..13802c4 100644
--- a/.docker/config/Dockerfile
+++ b/.docker/config/Dockerfile
@@ -1,4 +1,4 @@
-FROM php:5.6-cli
+FROM php:5.5-cli
 
 #
 # Tools & libraries
diff --git a/composer.json b/composer.json
index 49e759b..7c10d15 100644
--- a/composer.json
+++ b/composer.json
@@ -11,18 +11,18 @@
         }
     ],
     "require": {
-        "php": ">=5.6",
+        "php": ">=5.5.9",
         "fguillot/json-rpc": "^1.2",
         "wiosna/common-library": "~0.0.1"
     },
     "require-dev": {
-        "phpunit/phpunit": "^5.7",
-        "squizlabs/php_codesniffer": "^2.9",
-        "phpmd/phpmd": "^2.6",
-        "sebastian/phpcpd": "^3.0",
+        "friendsofphp/php-cs-fixer": "^2.2",
         "pdepend/pdepend": "^2.5",
-        "phploc/phploc": "^4.0",
-        "friendsofphp/php-cs-fixer": "^2.6"
+        "phploc/phploc": "^2.1",
+        "phpmd/phpmd": "^2.6",
+        "phpunit/phpunit": "^4.8",
+        "sebastian/phpcpd": "^2.0",
+        "squizlabs/php_codesniffer": "^2.9"
     },
     "autoload": {
         "psr-4": {
diff --git a/tests/Client/ClientTest.php b/tests/Client/ClientTest.php
index fb5fa03..11bb427 100644
--- a/tests/Client/ClientTest.php
+++ b/tests/Client/ClientTest.php
@@ -45,7 +45,7 @@ class ClientTest extends BaseTestCase
      */
     public function testRunWithIncorrectMethod($incorrectMethod)
     {
-        $this->expectException(UnknownMethodException::class);
+        $this->setExpectedException(UnknownMethodException::class);
 
         $client = new Client($this->configuration);
         $client->run($incorrectMethod);
@@ -61,8 +61,8 @@ class ClientTest extends BaseTestCase
      */
     public function testRun($method, $arguments, $debugMode, $expectedRawData)
     {
-        $sessionManager = $this->createMock(SessionManager::class);
-        $rpcClientManager = $this->createMock(JsonRpcClientManager::class);
+        $sessionManager = $this->getMock(SessionManager::class, [], [], '', false);
+        $rpcClientManager = $this->getMock(JsonRpcClientManager::class, [], [], '', false);
 
         $rpcClientManager
             ->expects(static::any())
diff --git a/tests/Configuration/ConnectionConfigurationTest.php b/tests/Configuration/ConnectionConfigurationTest.php
index 3f1883e..a89f5a5 100644
--- a/tests/Configuration/ConnectionConfigurationTest.php
+++ b/tests/Configuration/ConnectionConfigurationTest.php
@@ -47,7 +47,7 @@ class ConnectionConfigurationTest extends BaseTestCase
      */
     public function testConstructorWithEmptyBaseUrl($emptyBaseUrl)
     {
-        $this->expectException(InvalidUrlException::class);
+        $this->setExpectedException(InvalidUrlException::class);
         new ConnectionConfiguration($emptyBaseUrl, '', '');
     }
 
@@ -57,7 +57,7 @@ class ConnectionConfigurationTest extends BaseTestCase
      */
     public function testConstructorWithInvalidBaseUrl($invalidBaseUrl)
     {
-        $this->expectException(InvalidUrlException::class);
+        $this->setExpectedException(InvalidUrlException::class);
         new ConnectionConfiguration($invalidBaseUrl, '', '');
     }
 
diff --git a/tests/Manager/JsonRpcClientManagerTest.php b/tests/Manager/JsonRpcClientManagerTest.php
index 30d182d..718f59e 100644
--- a/tests/Manager/JsonRpcClientManagerTest.php
+++ b/tests/Manager/JsonRpcClientManagerTest.php
@@ -40,7 +40,7 @@ class JsonRpcClientManagerTest extends BaseTestCase
 
     public function testRunMethodWithEmptyArrayReturned()
     {
-        $rpcClient = $this->createMock(RpcClient::class);
+        $rpcClient = $this->getMock(RpcClient::class);
 
         $manager = $this
             ->getMockBuilder(JsonRpcClientManager::class)
@@ -68,8 +68,8 @@ class JsonRpcClientManagerTest extends BaseTestCase
 
     public function testRunMethodWithRawDataReturned()
     {
-        $rpcClient = $this->createMock(RpcClient::class);
-        $manager = $this->createPartialMock(JsonRpcClientManager::class, ['getRpcClient']);
+        $rpcClient = $this->getMock(RpcClient::class);
+        $manager = $this->getMock(JsonRpcClientManager::class, ['getRpcClient'], [], '', false);
 
         $rpcClient
             ->expects(static::once())
@@ -87,10 +87,10 @@ class JsonRpcClientManagerTest extends BaseTestCase
 
     public function testRunMethodWithException()
     {
-        $this->expectException(InvalidResultOfMethodRunException::class);
+        $this->setExpectedException(InvalidResultOfMethodRunException::class);
 
-        $manager = $this->createPartialMock(JsonRpcClientManager::class, ['getRpcClient']);
-        $rpcClient = $this->createMock(RpcClient::class);
+        $manager = $this->getMock(JsonRpcClientManager::class, ['getRpcClient'], [], '', false);
+        $rpcClient = $this->getMock(RpcClient::class);
 
         $rpcClient
             ->expects(self::once())
diff --git a/tests/Manager/SessionManagerTest.php b/tests/Manager/SessionManagerTest.php
index 158bcb5..11dc52d 100644
--- a/tests/Manager/SessionManagerTest.php
+++ b/tests/Manager/SessionManagerTest.php
@@ -29,10 +29,9 @@ class SessionManagerTest extends BaseTestCase
 
     public function testGetSessionKeyWhenFailedWithoutReason()
     {
-        $this->expectException(CreateSessionKeyFailedException::class);
-        $this->expectExceptionMessage('Create of the session key has failed');
+        $this->setExpectedException(CreateSessionKeyFailedException::class, 'Create of the session key has failed');
 
-        $clientManager = $this->createMock(JsonRpcClientManager::class);
+        $clientManager = $this->getMock(JsonRpcClientManager::class, [], [], '', false);
 
         $clientManager
             ->expects(static::any())
@@ -46,10 +45,10 @@ class SessionManagerTest extends BaseTestCase
     {
         $reason = 'Invalid credentials';
 
-        $this->expectException(CreateSessionKeyFailedException::class);
-        $this->expectExceptionMessage(sprintf('Create of the session key has failed. Reason: \'%s\'.', $reason));
+        $message = sprintf('Create of the session key has failed. Reason: \'%s\'.', $reason);
+        $this->setExpectedException(CreateSessionKeyFailedException::class, $message);
 
-        $clientManager = $this->createMock(JsonRpcClientManager::class);
+        $clientManager = $this->getMock(JsonRpcClientManager::class, [], [], '', false);
 
         $clientManager
             ->expects(static::any())
@@ -63,7 +62,7 @@ class SessionManagerTest extends BaseTestCase
 
     public function testGetSessionKey()
     {
-        $clientManager = $this->createMock(JsonRpcClientManager::class);
+        $clientManager = $this->getMock(JsonRpcClientManager::class, [], [], '', false);
 
         $clientManager
             ->expects(static::any())
@@ -76,7 +75,7 @@ class SessionManagerTest extends BaseTestCase
 
     public function testReleaseSessionKey()
     {
-        $clientManager = $this->createMock(JsonRpcClientManager::class);
+        $clientManager = $this->getMock(JsonRpcClientManager::class, [], [], '', false);
 
         $clientManager
             ->expects(static::any())
diff --git a/tests/Result/Collection/ParticipantsTest.php b/tests/Result/Collection/ParticipantsTest.php
index 114aca1..51be294 100644
--- a/tests/Result/Collection/ParticipantsTest.php
+++ b/tests/Result/Collection/ParticipantsTest.php
@@ -52,19 +52,19 @@ class ParticipantsTest extends BaseTestCase
 
     public function testAdd()
     {
-        $this->expectException(DisabledMethodException::class);
+        $this->setExpectedException(DisabledMethodException::class);
         (new Participants())->add('');
     }
 
     public function testAddMultiple()
     {
-        $this->expectException(DisabledMethodException::class);
+        $this->setExpectedException(DisabledMethodException::class);
         (new Participants())->addMultiple([]);
     }
 
     public function testHas()
     {
-        $this->expectException(DisabledMethodException::class);
+        $this->setExpectedException(DisabledMethodException::class);
         (new Participants())->has(new Participant());
     }
 
diff --git a/tests/Result/Collection/SurveysSummariesTest.php b/tests/Result/Collection/SurveysSummariesTest.php
index 219d712..585b2e8 100644
--- a/tests/Result/Collection/SurveysSummariesTest.php
+++ b/tests/Result/Collection/SurveysSummariesTest.php
@@ -44,19 +44,19 @@ class SurveysSummariesTest extends BaseTestCase
 
     public function testAdd()
     {
-        $this->expectException(DisabledMethodException::class);
+        $this->setExpectedException(DisabledMethodException::class);
         (new SurveysSummaries())->add('');
     }
 
     public function testAddMultiple()
     {
-        $this->expectException(DisabledMethodException::class);
+        $this->setExpectedException(DisabledMethodException::class);
         (new SurveysSummaries())->addMultiple([]);
     }
 
     public function testHas()
     {
-        $this->expectException(DisabledMethodException::class);
+        $this->setExpectedException(DisabledMethodException::class);
         (new SurveysSummaries())->has(new SurveySummary());
     }
 
diff --git a/tests/Result/Processor/ResultProcessorTest.php b/tests/Result/Processor/ResultProcessorTest.php
index 2d98225..fe5441e 100644
--- a/tests/Result/Processor/ResultProcessorTest.php
+++ b/tests/Result/Processor/ResultProcessorTest.php
@@ -82,7 +82,7 @@ class ResultProcessorTest extends BaseTestCase
 
     public function testRunWithUnknownResultClass()
     {
-        $this->expectException(UnknownInstanceOfResultItem::class);
+        $this->setExpectedException(UnknownInstanceOfResultItem::class);
 
         $rawData = [
             'lorem' => 'ipsum',
diff --git a/tests/Result/ResultTest.php b/tests/Result/ResultTest.php
index 4520826..6258abd 100644
--- a/tests/Result/ResultTest.php
+++ b/tests/Result/ResultTest.php
@@ -128,7 +128,7 @@ class ResultTest extends BaseTestCase
 
     public function testGetDataUsingProcessedDataWhoCannotBeProcessed()
     {
-        $this->expectException(CannotProcessDataException::class);
+        $this->setExpectedException(CannotProcessDataException::class);
         $this->statusInsteadDataResult->getData();
     }
 
diff --git a/tests/Service/ParticipantServiceTest.php b/tests/Service/ParticipantServiceTest.php
index 19e7a8d..5c5acf5 100644
--- a/tests/Service/ParticipantServiceTest.php
+++ b/tests/Service/ParticipantServiceTest.php
@@ -112,9 +112,7 @@ class ParticipantServiceTest extends BaseTestCase
     public function testGetParticipantDetailsWithException()
     {
         $exception = new CannotProcessDataException(ReasonType::NOT_EXISTING_SURVEY_ID);
-
-        $this->expectException(CannotProcessDataException::class);
-        $this->expectExceptionMessage($exception->getMessage());
+        $this->setExpectedException(CannotProcessDataException::class, $exception->getMessage());
 
         $rpcClientManager = $this->getJsonRpcClientManagerWithException(1, $exception);
         $sessionManager = $this->getSessionManager();
@@ -158,7 +156,7 @@ class ParticipantServiceTest extends BaseTestCase
 
     public function testHasParticipantFilledSurveyWithoutParticipants()
     {
-        $this->expectException(MissingParticipantOfSurveyException::class);
+        $this->setExpectedException(MissingParticipantOfSurveyException::class);
 
         $rpcClientManager = $this->getJsonRpcClientManager(1);
         $sessionManager = $this->getSessionManager();
@@ -178,7 +176,7 @@ class ParticipantServiceTest extends BaseTestCase
 
     public function testHasParticipantFilledSurveyUsingNotExistingParticipant()
     {
-        $this->expectException(MissingParticipantOfSurveyException::class);
+        $this->setExpectedException(MissingParticipantOfSurveyException::class);
 
         $rpcClientManager = $this->getJsonRpcClientManager(1);
         $sessionManager = $this->getSessionManager();
@@ -253,7 +251,7 @@ class ParticipantServiceTest extends BaseTestCase
      */
     private function getSessionManager()
     {
-        return $this->createMock(SessionManager::class);
+        return $this->getMock(SessionManager::class, [], [], '', false);
     }
 
     /**
@@ -265,7 +263,7 @@ class ParticipantServiceTest extends BaseTestCase
      */
     private function getJsonRpcClientManager($runMethodCallCount, array $runMethodCallResults = [])
     {
-        $rpcClientManager = $this->createMock(JsonRpcClientManager::class);
+        $rpcClientManager = $this->getMock(JsonRpcClientManager::class, [], [], '', false);
 
         $mocker = $rpcClientManager
             ->expects(static::exactly($runMethodCallCount))
@@ -297,7 +295,7 @@ class ParticipantServiceTest extends BaseTestCase
      */
     private function getJsonRpcClientManagerWithException($runMethodCallCount, Exception $exception)
     {
-        $rpcClientManager = $this->createMock(JsonRpcClientManager::class);
+        $rpcClientManager = $this->getMock(JsonRpcClientManager::class, [], [], '', false);
 
         $rpcClientManager
             ->expects(static::exactly($runMethodCallCount))
diff --git a/tests/Service/SurveyServiceTest.php b/tests/Service/SurveyServiceTest.php
index 9d87c9c..38d137b 100644
--- a/tests/Service/SurveyServiceTest.php
+++ b/tests/Service/SurveyServiceTest.php
@@ -100,7 +100,7 @@ class SurveyServiceTest extends BaseTestCase
 
     public function testGetAllSurveysWithNoTableException()
     {
-        $this->expectException(CannotProcessDataException::class);
+        $this->setExpectedException(CannotProcessDataException::class);
         $exception = new CannotProcessDataException(ReasonType::NO_TOKEN_TABLE);
 
         $rpcClientManager = $this->getJsonRpcClientManagerWithException(1, $exception);
@@ -224,9 +224,7 @@ class SurveyServiceTest extends BaseTestCase
     public function testGetSurveyParticipantsWithNotExistingSurveyException()
     {
         $exception = new CannotProcessDataException(ReasonType::NOT_EXISTING_SURVEY_ID);
-
-        $this->expectException(CannotProcessDataException::class);
-        $this->expectExceptionMessage($exception->getMessage());
+        $this->setExpectedException(CannotProcessDataException::class, $exception->getMessage());
 
         $runMethodCallResults = [
             [
@@ -332,7 +330,7 @@ class SurveyServiceTest extends BaseTestCase
 
     public function testGetSurveyParticipantsWithNoTableException()
     {
-        $this->expectException(CannotProcessDataException::class);
+        $this->setExpectedException(CannotProcessDataException::class);
         $exception = new CannotProcessDataException(ReasonType::NO_TOKEN_TABLE);
 
         $rpcClientManager = $this->getJsonRpcClientManagerWithException(1, $exception);
@@ -344,7 +342,7 @@ class SurveyServiceTest extends BaseTestCase
 
     public function testGetSurveyParticipantsWithNoParticipantsException()
     {
-        $this->expectException(CannotProcessDataException::class);
+        $this->setExpectedException(CannotProcessDataException::class);
         $exception = new CannotProcessDataException(ReasonType::NO_PARTICIPANTS_FOUND);
 
         $rpcClientManager = $this->getJsonRpcClientManagerWithException(1, $exception);
@@ -356,7 +354,7 @@ class SurveyServiceTest extends BaseTestCase
 
     public function testAddParticipantForNotExistingSurvey()
     {
-        $this->expectException(CannotProcessDataException::class);
+        $this->setExpectedException(CannotProcessDataException::class);
         $exception = new CannotProcessDataException(ReasonType::NOT_EXISTING_SURVEY_ID);
 
         $rpcClientManager = $this->getJsonRpcClientManagerWithException(1, $exception);
@@ -466,7 +464,7 @@ class SurveyServiceTest extends BaseTestCase
 
     public function testGetSurveyTokenCountWithException()
     {
-        $this->expectException(MissingSurveySummaryException::class);
+        $this->setExpectedException(MissingSurveySummaryException::class);
 
         $runMethodCallResults = [
             null,
@@ -496,7 +494,7 @@ class SurveyServiceTest extends BaseTestCase
      */
     private function getSessionManager()
     {
-        return $this->createMock(SessionManager::class);
+        return $this->getMock(SessionManager::class, [], [], '', false);
     }
 
     /**
@@ -508,7 +506,7 @@ class SurveyServiceTest extends BaseTestCase
      */
     private function getJsonRpcClientManager($runMethodCallCount, array $runMethodCallResults = [])
     {
-        $rpcClientManager = $this->createMock(JsonRpcClientManager::class);
+        $rpcClientManager = $this->getMock(JsonRpcClientManager::class, [], [], '', false);
 
         $mocker = $rpcClientManager
             ->expects(static::exactly($runMethodCallCount))
@@ -540,7 +538,7 @@ class SurveyServiceTest extends BaseTestCase
      */
     private function getJsonRpcClientManagerWithException($runMethodCallCount, Exception $exception)
     {
-        $rpcClientManager = $this->createMock(JsonRpcClientManager::class);
+        $rpcClientManager = $this->getMock(JsonRpcClientManager::class, [], [], '', false);
 
         $rpcClientManager
             ->expects(static::exactly($runMethodCallCount))
diff --git a/tests/Type/MethodTypeTest.php b/tests/Type/MethodTypeTest.php
index 5a27073..f0041e4 100644
--- a/tests/Type/MethodTypeTest.php
+++ b/tests/Type/MethodTypeTest.php
@@ -33,7 +33,7 @@ class MethodTypeTest extends BaseTypeTestCase
      */
     public function testGetValidatedMethodWithIncorrectMethod($incorrectMethod)
     {
-        $this->expectException(UnknownMethodException::class);
+        $this->setExpectedException(UnknownMethodException::class);
         MethodType::getValidatedMethod($incorrectMethod);
     }
 
@@ -52,7 +52,7 @@ class MethodTypeTest extends BaseTypeTestCase
      */
     public function testIsResultIterableWithIncorrectMethod($incorrectMethod)
     {
-        $this->expectException(UnknownMethodException::class);
+        $this->setExpectedException(UnknownMethodException::class);
         MethodType::isResultIterable($incorrectMethod);
     }