fix deprecation for Extension class

src/DAMA/DoctrineTestBundle/DependencyInjection/DAMADoctrineTestExtension.php

@@ -3,7 +3,7 @@
 namespace DAMA\DoctrineTestBundle\DependencyInjection;
 
 use Symfony\Component\DependencyInjection\ContainerBuilder;
-use Symfony\Component\HttpKernel\DependencyInjection\Extension;
+use Symfony\Component\DependencyInjection\Extension\Extension;
 
 class DAMADoctrineTestExtension extends Extension
 {