Moved test Postmark class to separate file

tests/Stampie/Tests/GitHub/Issue4Test.php

@@ -5,8 +5,6 @@
 use Stampie\Adapter\Response;
 use Stampie\Tests\Mailer\TestPostmark;
 
-require_once __DIR__.'/../Mailer/PostmarkTest.php';
-
 /**
  * @author Henrik Bjornskov <henrik@bjrnskov.dk>
  */

tests/Stampie/Tests/Mailer/PostmarkTest.php

@@ -96,26 +96,3 @@ public function handleDataProvider()
         );
     }
 }
-
-class TestPostmark extends Postmark
-{
-    public function getEndpoint()
-    {
-        return parent::getEndpoint();
-    }
-
-    public function handle(ResponseInterface $response)
-    {
-        parent::handle($response);
-    }
-
-    public function getHeaders()
-    {
-        return parent::getHeaders();
-    }
-
-    public function format(MessageInterface $message)
-    {
-        return parent::format($message);
-    }
-}

tests/Stampie/Tests/Mailer/TestPostmark.php

@@ -0,0 +1,30 @@
+<?php
+
+namespace Stampie\Tests\Mailer;
+
+use Stampie\Mailer\Postmark;
+use Stampie\Adapter\ResponseInterface;
+use Stampie\MessageInterface;
+
+class TestPostmark extends Postmark
+{
+    public function getEndpoint()
+    {
+        return parent::getEndpoint();
+    }
+
+    public function handle(ResponseInterface $response)
+    {
+        parent::handle($response);
+    }
+
+    public function getHeaders()
+    {
+        return parent::getHeaders();
+    }
+
+    public function format(MessageInterface $message)
+    {
+        return parent::format($message);
+    }
+}