diff --git a/.travis.yml b/.travis.yml
index fa7b39c8..5f9dcf9a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,19 +1,30 @@
 language: php
 
 php:
-  - 5.4
-  - 5.5
   - 5.6
   - 7.0
   - 7.1
   - 7.2
-  - hhvm
+
+# This triggers builds to run on the new TravisCI infrastructure.
+# See: http://docs.travis-ci.com/user/workers/container-based-infrastructure/
+sudo: false
+
+cache:
+  directories:
+    - $HOME/.composer/cache
+
+env:
+  global:
+    - setup=basic
 
 matrix:
-  allow_failures:
-    - php: hhvm
+  include:
+    - php: 5.6
+      env: setup=lowest
 
-before_script:
-  - composer install -n --dev --prefer-source
+install:
+  - if [[ $setup = 'basic' ]]; then travis_retry composer install --prefer-dist --no-interaction; fi
+  - if [[ $setup = 'lowest' ]]; then travis_retry composer update --prefer-dist --no-interaction --prefer-lowest --prefer-stable; fi
 
 script: vendor/bin/phpcs --standard=PSR2 src && vendor/bin/phpunit --coverage-text
diff --git a/composer.json b/composer.json
index b03077ec..671d2c0d 100644
--- a/composer.json
+++ b/composer.json
@@ -28,16 +28,23 @@
         "psr-4": { "Omnipay\\AuthorizeNet\\" : "src/" }
     },
     "require": {
-        "omnipay/common": "~2.5",
+        "omnipay/common": "^3",
         "ext-json": "*",
         "ext-simplexml": "*"
     },
     "require-dev": {
-        "omnipay/tests": "~2.0"
+        "omnipay/tests": "^3",
+        "squizlabs/php_codesniffer": "^3"
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "2.0.x-dev"
+            "dev-master": "3.0.x-dev"
         }
-    }
+    },
+    "scripts": {
+        "test": "phpunit",
+        "check-style": "phpcs -p --standard=PSR2 src/",
+        "fix-style": "phpcbf -p --standard=PSR2 src/"
+    },
+    "prefer-stable": true
 }
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index a35b7362..535809e1 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -14,9 +14,6 @@
             <directory>./tests/</directory>
         </testsuite>
     </testsuites>
-    <listeners>
-        <listener class="Mockery\Adapter\Phpunit\TestListener" file="vendor/mockery/mockery/library/Mockery/Adapter/Phpunit/TestListener.php" />
-    </listeners>
     <filter>
         <whitelist>
             <directory>./src</directory>
diff --git a/src/Message/AIMAbstractRequest.php b/src/Message/AIMAbstractRequest.php
index 96799cf8..fd368c65 100644
--- a/src/Message/AIMAbstractRequest.php
+++ b/src/Message/AIMAbstractRequest.php
@@ -170,9 +170,9 @@ public function sendData($data)
     {
         $headers = array('Content-Type' => 'text/xml; charset=utf-8');
         $data = $data->saveXml();
-        $httpResponse = $this->httpClient->post($this->getEndpoint(), $headers, $data)->send();
+        $httpResponse = $this->httpClient->request('POST', $this->getEndpoint(), $headers, $data);
 
-        return $this->response = new AIMResponse($this, $httpResponse->getBody());
+        return $this->response = new AIMResponse($this, $httpResponse->getBody()->getContents());
     }
 
     /**
diff --git a/src/Message/AIMResponse.php b/src/Message/AIMResponse.php
index 4c99215e..5c25a8cc 100644
--- a/src/Message/AIMResponse.php
+++ b/src/Message/AIMResponse.php
@@ -48,7 +48,7 @@ public function isSuccessful()
      */
     public function getResultCode()
     {
-        return intval((string)$this->data->transactionResponse[0]->responseCode);
+        return intval((string)$this->data->transactionResponse->responseCode);
     }
 
     /**
@@ -60,13 +60,12 @@ public function getReasonCode()
     {
         $code = null;
 
-        if (isset($this->data->transactionResponse[0]->messages)) {
+        if (isset($this->data->transactionResponse->messages)) {
             // In case of a successful transaction, a "messages" element is present
-            $code = intval((string)$this->data->transactionResponse[0]->messages[0]->message[0]->code);
-
-        } elseif (isset($this->data->transactionResponse[0]->errors)) {
+            $code = intval((string)$this->data->transactionResponse->messages->message->code);
+        } elseif (isset($this->data->transactionResponse->errors)) {
             // In case of an unsuccessful transaction, an "errors" element is present
-            $code = intval((string)$this->data->transactionResponse[0]->errors[0]->error[0]->errorCode);
+            $code = intval((string)$this->data->transactionResponse->errors->error->errorCode);
         }
 
         return $code;
@@ -81,13 +80,12 @@ public function getMessage()
     {
         $message = null;
 
-        if (isset($this->data->transactionResponse[0]->messages)) {
+        if (isset($this->data->transactionResponse->messages)) {
             // In case of a successful transaction, a "messages" element is present
-            $message = (string)$this->data->transactionResponse[0]->messages[0]->message[0]->description;
-
-        } elseif (isset($this->data->transactionResponse[0]->errors)) {
+            $message = (string)$this->data->transactionResponse->messages->message->description;
+        } elseif (isset($this->data->transactionResponse->errors)) {
             // In case of an unsuccessful transaction, an "errors" element is present
-            $message = (string)$this->data->transactionResponse[0]->errors[0]->error[0]->errorText;
+            $message = (string)$this->data->transactionResponse->errors->error->errorText;
         }
 
         return $message;
@@ -95,7 +93,7 @@ public function getMessage()
 
     public function getAuthorizationCode()
     {
-        return (string)$this->data->transactionResponse[0]->authCode;
+        return (string)$this->data->transactionResponse->authCode;
     }
 
     /**
@@ -105,7 +103,7 @@ public function getAuthorizationCode()
      */
     public function getAVSCode()
     {
-        return (string)$this->data->transactionResponse[0]->avsResultCode;
+        return (string)$this->data->transactionResponse->avsResultCode;
     }
 
     /**
@@ -118,7 +116,7 @@ public function getAVSCode()
     public function getTransactionReference($serialize = true)
     {
         if ($this->isSuccessful()) {
-            $body = $this->data->transactionResponse[0];
+            $body = $this->data->transactionResponse;
             $transactionRef = new TransactionReference();
             $transactionRef->setApprovalCode((string)$body->authCode);
             $transactionRef->setTransId((string)$body->transId);
diff --git a/src/Message/CIMAbstractRequest.php b/src/Message/CIMAbstractRequest.php
index 171f0340..2c8fcf81 100644
--- a/src/Message/CIMAbstractRequest.php
+++ b/src/Message/CIMAbstractRequest.php
@@ -101,8 +101,8 @@ public function sendData($data)
     {
         $headers = array('Content-Type' => 'text/xml; charset=utf-8');
         $data = $data->saveXml();
-        $httpResponse = $this->httpClient->post($this->getEndpoint(), $headers, $data)->send();
+        $httpResponse = $this->httpClient->request('POST', $this->getEndpoint(), $headers, $data);
 
-        return $this->response = new CIMResponse($this, $httpResponse->getBody());
+        return $this->response = new CIMResponse($this, $httpResponse->getBody()->getContents());
     }
 }
diff --git a/src/Message/CIMAbstractResponse.php b/src/Message/CIMAbstractResponse.php
index 28916d9f..63e386a4 100644
--- a/src/Message/CIMAbstractResponse.php
+++ b/src/Message/CIMAbstractResponse.php
@@ -19,7 +19,7 @@ public function __construct(RequestInterface $request, $data)
         // Check if this is an error response
         $isError = strpos((string)$data, '<ErrorResponse');
 
-        $xmlRootElement = $isError !== false ? 'ErrorResponse' : $this->responseType;
+        $xmlRootElement = ($isError !== false ? 'ErrorResponse' : $this->responseType);
         // Strip out the xmlns junk so that PHP can parse the XML
         $xml = preg_replace('/<' . $xmlRootElement . '[^>]+>/', '<' . $xmlRootElement . '>', (string)$data);
 
@@ -58,7 +58,6 @@ public function getResultCode()
                 return 3;
             default:
                 return null;
-
         }
     }
 
@@ -125,8 +124,6 @@ public function getCardReference()
     }
 
     /**
-     * http://bookofzeus.com/articles/convert-simplexml-object-into-php-array/
-     *
      * Convert a simpleXMLElement in to an array
      *
      * @param \SimpleXMLElement $xml
diff --git a/src/Message/CIMAuthorizeRequest.php b/src/Message/CIMAuthorizeRequest.php
index dc8d9252..aa440eb1 100644
--- a/src/Message/CIMAuthorizeRequest.php
+++ b/src/Message/CIMAuthorizeRequest.php
@@ -14,7 +14,6 @@ protected function addPayment(\SimpleXMLElement $data)
         if ($this->isCardPresent()) {
             // Prefer the track data if present over the payment profile (better rate)
             return parent::addPayment($data);
-
         } else {
             $this->validate('cardReference');
 
diff --git a/src/Message/CIMCreateCardRequest.php b/src/Message/CIMCreateCardRequest.php
index 09ac180a..5a50da3f 100644
--- a/src/Message/CIMCreateCardRequest.php
+++ b/src/Message/CIMCreateCardRequest.php
@@ -152,9 +152,9 @@ public function sendData($data)
     {
         $headers = array('Content-Type' => 'text/xml; charset=utf-8');
         $data = $data->saveXml();
-        $httpResponse = $this->httpClient->post($this->getEndpoint(), $headers, $data)->send();
+        $httpResponse = $this->httpClient->request('POST', $this->getEndpoint(), $headers, $data);
 
-        $response = new CIMCreateCardResponse($this, $httpResponse->getBody());
+        $response = new CIMCreateCardResponse($this, $httpResponse->getBody()->getContents());
 
         if (!$response->isSuccessful() && $response->getReasonCode() == 'E00039') {
             // Duplicate profile. Try adding a new payment profile for the same profile and get the response
diff --git a/src/Message/CIMCreatePaymentProfileRequest.php b/src/Message/CIMCreatePaymentProfileRequest.php
index 5948165b..f2c4ed92 100644
--- a/src/Message/CIMCreatePaymentProfileRequest.php
+++ b/src/Message/CIMCreatePaymentProfileRequest.php
@@ -43,8 +43,8 @@ public function sendData($data)
     {
         $headers = array('Content-Type' => 'text/xml; charset=utf-8');
         $data = $data->saveXml();
-        $httpResponse = $this->httpClient->post($this->getEndpoint(), $headers, $data)->send();
+        $httpResponse = $this->httpClient->request('POST', $this->getEndpoint(), $headers, $data);
 
-        return $this->response = new CIMCreatePaymentProfileResponse($this, $httpResponse->getBody());
+        return $this->response = new CIMCreatePaymentProfileResponse($this, $httpResponse->getBody()->getContents());
     }
 }
diff --git a/src/Message/CIMGetPaymentProfileRequest.php b/src/Message/CIMGetPaymentProfileRequest.php
index a8da6cf6..2181fdc4 100644
--- a/src/Message/CIMGetPaymentProfileRequest.php
+++ b/src/Message/CIMGetPaymentProfileRequest.php
@@ -25,8 +25,8 @@ public function sendData($data)
     {
         $headers = array('Content-Type' => 'text/xml; charset=utf-8');
         $data = $data->saveXml();
-        $httpResponse = $this->httpClient->post($this->getEndpoint(), $headers, $data)->send();
+        $httpResponse = $this->httpClient->request('POST', $this->getEndpoint(), $headers, $data);
 
-        return $this->response = new CIMGetPaymentProfileResponse($this, $httpResponse->getBody());
+        return $this->response = new CIMGetPaymentProfileResponse($this, $httpResponse->getBody()->getContents());
     }
 }
diff --git a/src/Message/CIMGetProfileRequest.php b/src/Message/CIMGetProfileRequest.php
index 5f755475..caaea8e9 100644
--- a/src/Message/CIMGetProfileRequest.php
+++ b/src/Message/CIMGetProfileRequest.php
@@ -24,8 +24,8 @@ public function sendData($data)
     {
         $headers = array('Content-Type' => 'text/xml; charset=utf-8');
         $data = $data->saveXml();
-        $httpResponse = $this->httpClient->post($this->getEndpoint(), $headers, $data)->send();
+        $httpResponse = $this->httpClient->request('POST', $this->getEndpoint(), $headers, $data);
 
-        return $this->response = new CIMGetProfileResponse($this, $httpResponse->getBody());
+        return $this->response = new CIMGetProfileResponse($this, $httpResponse->getBody()->getContents());
     }
 }
diff --git a/src/Message/CIMUpdatePaymentProfileRequest.php b/src/Message/CIMUpdatePaymentProfileRequest.php
index 37a7e1a9..4677adfb 100644
--- a/src/Message/CIMUpdatePaymentProfileRequest.php
+++ b/src/Message/CIMUpdatePaymentProfileRequest.php
@@ -44,8 +44,8 @@ public function sendData($data)
     {
         $headers = array('Content-Type' => 'text/xml; charset=utf-8');
         $data = $data->saveXml();
-        $httpResponse = $this->httpClient->post($this->getEndpoint(), $headers, $data)->send();
+        $httpResponse = $this->httpClient->request('POST', $this->getEndpoint(), $headers, $data);
 
-        return $this->response = new CIMUpdatePaymentProfileResponse($this, $httpResponse->getBody());
+        return $this->response = new CIMUpdatePaymentProfileResponse($this, $httpResponse->getBody()->getContents());
     }
 }
diff --git a/src/Message/SIMAbstractRequest.php b/src/Message/SIMAbstractRequest.php
index 58ae790d..44833f35 100644
--- a/src/Message/SIMAbstractRequest.php
+++ b/src/Message/SIMAbstractRequest.php
@@ -170,9 +170,9 @@ protected function getBillingData()
 
     public function sendData($data)
     {
-        $httpResponse = $this->httpClient->post($this->getEndpoint(), null, $data)->send();
+        $httpResponse = $this->httpClient->request('POST', $this->getEndpoint(), [], http_build_query($data));
 
-        return $this->response = new AIMResponse($this, $httpResponse->getBody());
+        return $this->response = new AIMResponse($this, $httpResponse->getBody()->getContents());
     }
 
     public function getEndpoint()
diff --git a/tests/CIMGatewayTest.php b/tests/CIMGatewayTest.php
index 9e03603d..f4cfc41a 100644
--- a/tests/CIMGatewayTest.php
+++ b/tests/CIMGatewayTest.php
@@ -200,6 +200,7 @@ public function testPurchaseFailure()
 
     public function testRefundSuccess()
     {
+        self::markTestSkipped();
 //        $this->setMockHttpResponse('CIMRefundSuccess.txt');
 //
 //        $response = $this->gateway->refund($this->refundOptions)->send();
diff --git a/tests/Message/AIMAbstractRequestTest.php b/tests/Message/AIMAbstractRequestTest.php
index 04d01400..c16d1502 100644
--- a/tests/Message/AIMAbstractRequestTest.php
+++ b/tests/Message/AIMAbstractRequestTest.php
@@ -1,12 +1,12 @@
 <?php
 
-
 namespace Message;
 
-
 use Omnipay\AuthorizeNet\Message\AIMAbstractRequest;
+use Omnipay\Common\Http\ClientInterface;
+use Omnipay\Tests\TestCase;
 
-class AIMAbstractRequestTest extends \PHPUnit_Framework_TestCase
+class AIMAbstractRequestTest extends TestCase
 {
     /** @var AIMAbstractRequest */
     private $request;
@@ -16,8 +16,8 @@ public function setUp()
         $this->request = $this->getMockForAbstractClass(
             '\Omnipay\AuthorizeNet\Message\AIMAbstractRequest',
             array(
-                $this->getMock('\Guzzle\Http\ClientInterface'),
-                $this->getMock('\Symfony\Component\HttpFoundation\Request')
+                $this->createMock(ClientInterface::class),
+                $this->createMock('\Symfony\Component\HttpFoundation\Request')
             )
         );
     }
diff --git a/tests/Message/AIMResponseTest.php b/tests/Message/AIMResponseTest.php
index e0950474..392c20a3 100644
--- a/tests/Message/AIMResponseTest.php
+++ b/tests/Message/AIMResponseTest.php
@@ -18,7 +18,7 @@ public function getMockRequest($className = '\Omnipay\AuthorizeNet\Message\AIMAb
 
     public function testConstructEmpty()
     {
-        $this->setExpectedException('\Omnipay\Common\Exception\InvalidResponseException');
+        $this->expectException('\Omnipay\Common\Exception\InvalidResponseException');
         new AIMResponse($this->getMockRequest(), '');
     }
 
diff --git a/tests/Mock/CIMCreateCardFailure.txt b/tests/Mock/CIMCreateCardFailure.txt
index fe7bdc5a..86ce9e9e 100644
--- a/tests/Mock/CIMCreateCardFailure.txt
+++ b/tests/Mock/CIMCreateCardFailure.txt
@@ -1,8 +1,7 @@
 HTTP/1.1 200 OK
 Cache-Control: private
 Content-Length: 746
-Content-Type: text/xml;
-charset=utf-8
+Content-Type: text/xml; charset=utf-8
 Server: Microsoft-IIS/7.5
 X-AspNet-Version: 2.0.50727
 X-Powered-By: ASP.NET
diff --git a/tests/Mock/CIMCreateCardFailureWithDuplicate.txt b/tests/Mock/CIMCreateCardFailureWithDuplicate.txt
index 617eaaad..6fc83e3e 100644
--- a/tests/Mock/CIMCreateCardFailureWithDuplicate.txt
+++ b/tests/Mock/CIMCreateCardFailureWithDuplicate.txt
@@ -1,8 +1,7 @@
 HTTP/1.1 200 OK
 Cache-Control: private
 Content-Length: 746
-Content-Type: text/xml;
-charset=utf-8
+Content-Type: text/xml; charset=utf-8
 Server: Microsoft-IIS/7.5
 X-AspNet-Version: 2.0.50727
 X-Powered-By: ASP.NET
diff --git a/tests/Mock/CIMCreateCardSuccess.txt b/tests/Mock/CIMCreateCardSuccess.txt
index 97e06ed2..9e29f906 100644
--- a/tests/Mock/CIMCreateCardSuccess.txt
+++ b/tests/Mock/CIMCreateCardSuccess.txt
@@ -1,8 +1,7 @@
 HTTP/1.1 200 OK
 Cache-Control: private
 Content-Length: 746
-Content-Type: text/xml;
-charset=utf-8
+Content-Type: text/xml;charset=utf-8
 Server: Microsoft-IIS/7.5
 X-AspNet-Version: 2.0.50727
 X-Powered-By: ASP.NET
diff --git a/tests/Mock/CIMCreatePaymentProfileFailure.txt b/tests/Mock/CIMCreatePaymentProfileFailure.txt
index 91b28e6c..abfebdc9 100644
--- a/tests/Mock/CIMCreatePaymentProfileFailure.txt
+++ b/tests/Mock/CIMCreatePaymentProfileFailure.txt
@@ -1,8 +1,7 @@
 HTTP/1.1 200 OK
 Cache-Control: private
 Content-Length: 746
-Content-Type: text/xml;
-charset=utf-8
+Content-Type: text/xml; charset=utf-8
 Server: Microsoft-IIS/7.5
 X-AspNet-Version: 2.0.50727
 X-Powered-By: ASP.NET
diff --git a/tests/Mock/CIMCreatePaymentProfileFailureMaxProfileLimit.txt b/tests/Mock/CIMCreatePaymentProfileFailureMaxProfileLimit.txt
index 98b69db6..8d8ee7a9 100644
--- a/tests/Mock/CIMCreatePaymentProfileFailureMaxProfileLimit.txt
+++ b/tests/Mock/CIMCreatePaymentProfileFailureMaxProfileLimit.txt
@@ -1,8 +1,7 @@
 HTTP/1.1 200 OK
 Cache-Control: private
 Content-Length: 746
-Content-Type: text/xml;
-charset=utf-8
+Content-Type: text/xml; charset=utf-8
 Server: Microsoft-IIS/7.5
 X-AspNet-Version: 2.0.50727
 X-Powered-By: ASP.NET
diff --git a/tests/Mock/CIMCreatePaymentProfileSuccess.txt b/tests/Mock/CIMCreatePaymentProfileSuccess.txt
index 40bdb247..e860a255 100644
--- a/tests/Mock/CIMCreatePaymentProfileSuccess.txt
+++ b/tests/Mock/CIMCreatePaymentProfileSuccess.txt
@@ -1,8 +1,7 @@
 HTTP/1.1 200 OK
 Cache-Control: private
 Content-Length: 746
-Content-Type: text/xml;
-charset=utf-8
+Content-Type: text/xml; charset=utf-8
 Server: Microsoft-IIS/7.5
 X-AspNet-Version: 2.0.50727
 X-Powered-By: ASP.NET
diff --git a/tests/Mock/CIMGetMultipleProfilesSuccess.txt b/tests/Mock/CIMGetMultipleProfilesSuccess.txt
index 8fedf2f1..33f23ab3 100644
--- a/tests/Mock/CIMGetMultipleProfilesSuccess.txt
+++ b/tests/Mock/CIMGetMultipleProfilesSuccess.txt
@@ -1,8 +1,7 @@
 HTTP/1.1 200 OK
 Cache-Control: private
 Content-Length: 746
-Content-Type: text/xml;
-charset=utf-8
+Content-Type: text/xml; charset=utf-8
 Server: Microsoft-IIS/7.5
 X-AspNet-Version: 2.0.50727
 X-Powered-By: ASP.NET
diff --git a/tests/Mock/CIMGetPaymentProfileSuccess.txt b/tests/Mock/CIMGetPaymentProfileSuccess.txt
index 9c4c6782..8e51908f 100644
--- a/tests/Mock/CIMGetPaymentProfileSuccess.txt
+++ b/tests/Mock/CIMGetPaymentProfileSuccess.txt
@@ -1,8 +1,7 @@
 HTTP/1.1 200 OK
 Cache-Control: private
 Content-Length: 746
-Content-Type: text/xml;
-charset=utf-8
+Content-Type: text/xml;charset=utf-8
 Server: Microsoft-IIS/7.5
 X-AspNet-Version: 2.0.50727
 X-Powered-By: ASP.NET
diff --git a/tests/Mock/CIMGetSingleProfileSuccess.txt b/tests/Mock/CIMGetSingleProfileSuccess.txt
index 27d4120d..3beb50c0 100644
--- a/tests/Mock/CIMGetSingleProfileSuccess.txt
+++ b/tests/Mock/CIMGetSingleProfileSuccess.txt
@@ -1,8 +1,7 @@
 HTTP/1.1 200 OK
 Cache-Control: private
 Content-Length: 746
-Content-Type: text/xml;
-charset=utf-8
+Content-Type: text/xml; charset=utf-8
 Server: Microsoft-IIS/7.5
 X-AspNet-Version: 2.0.50727
 X-Powered-By: ASP.NET
diff --git a/tests/Mock/CIMUpdatePaymentProfileSuccess.txt b/tests/Mock/CIMUpdatePaymentProfileSuccess.txt
index 348ab7e0..7d7abd97 100644
--- a/tests/Mock/CIMUpdatePaymentProfileSuccess.txt
+++ b/tests/Mock/CIMUpdatePaymentProfileSuccess.txt
@@ -1,8 +1,7 @@
 HTTP/1.1 200 OK
 Cache-Control: private
 Content-Length: 746
-Content-Type: text/xml;
-charset=utf-8
+Content-Type: text/xml; charset=utf-8
 Server: Microsoft-IIS/7.5
 X-AspNet-Version: 2.0.50727
 X-Powered-By: ASP.NET
diff --git a/tests/Model/CardReferenceTest.php b/tests/Model/CardReferenceTest.php
index d471d2a4..7de6fa62 100644
--- a/tests/Model/CardReferenceTest.php
+++ b/tests/Model/CardReferenceTest.php
@@ -2,7 +2,10 @@
 
 namespace Omnipay\AuthorizeNet\Model;
 
-class CardReferenceTest extends \PHPUnit_Framework_TestCase
+
+use Omnipay\Tests\TestCase;
+
+class CardReferenceTest extends TestCase
 {
     private $data;
     /** @var CardReference */
diff --git a/tests/Model/TransactionReferenceTest.php b/tests/Model/TransactionReferenceTest.php
index b0cf0c80..8c0be267 100644
--- a/tests/Model/TransactionReferenceTest.php
+++ b/tests/Model/TransactionReferenceTest.php
@@ -2,7 +2,9 @@
 
 namespace Omnipay\AuthorizeNet\Model;
 
-class TransactionReferenceTest extends \PHPUnit_Framework_TestCase
+use Omnipay\Tests\TestCase;
+
+class TransactionReferenceTest extends TestCase
 {
     private $data;
     /** @var TransactionReference */