[Minor] Remove dead code & fix phpdoc

src/Silex/ServiceProviderInterface.php

@@ -23,8 +23,6 @@ interface ServiceProviderInterface
      *
      * This method should only be used to configure services and parameters.
      * It should not get services.
-     *
-     * @param Application $app An Application instance
      */
     public function register(Application $app);
 

tests/Silex/Tests/CallbackServicesTest.php

@@ -13,7 +13,6 @@ namespace Silex\Tests;
 
 use Silex\Application;
 use Symfony\Component\HttpFoundation\Request;
-use Symfony\Component\HttpFoundation\Response;
 use Silex\Provider\ServiceControllerServiceProvider;
 
 /**