Update phpunit.xml

Author: WizardLoop

phpunit.xml

@@ -14,12 +14,17 @@
     </testsuites>
 
     <coverage>
-        <directory>src</directory>
         <report>
             <clover outputFile="tests/coverage/clover.xml"/>
         </report>
     </coverage>
 
+    <filter>
+        <whitelist processUncoveredFiles="true">
+            <directory suffix=".php">src</directory>
+        </whitelist>
+    </filter>
+
     <php>
         <ini name="error_reporting" value="-1"/>
         <server name="APP_ENV" value="test"/>