Update README.md (php-debugbar#535)

Author: yagiz-dev

README.md

@@ -28,7 +28,7 @@ Includes collectors for:
   - [Propel](http://propelorm.org/)
   - [Slim](http://slimframework.com)
   - [Swift Mailer](http://swiftmailer.org/)
-  - [Twig](http://twig.sensiolabs.org/)
+  - [Twig](http://twig.symfony.com/)
 
 Checkout the [demo](https://github.com/maximebf/php-debugbar/tree/master/demo) for
 examples and [phpdebugbar.com](http://phpdebugbar.com) for a live example.