Don't generate code coverage for test code.

phpunit.xml.dist

@@ -23,6 +23,7 @@
             <directory>./src/Symfony/</directory>
             <exclude>
                 <directory>./src/Symfony/Bundle/*/Resources</directory>
+                <directory>./src/Symfony/Bundle/*/Tests</directory>
                 <directory>./src/Symfony/Component/*/Resources</directory>
             </exclude>
         </whitelist>