Restrict test coverage report to src directory

Author: amacneil

phpunit.xml.dist

@@ -17,4 +17,9 @@
     <listeners>
         <listener class="Mockery\Adapter\Phpunit\TestListener" file="vendor/mockery/mockery/library/Mockery/Adapter/Phpunit/TestListener.php" />
     </listeners>
+    <filter>
+        <whitelist>
+            <directory>./src</directory>
+        </whitelist>
+    </filter>
 </phpunit>