Fix Service Provider example
Fix Service Provider example

\Slim\App is no longer a instance of \Pimple\Container. This affects registration of Pimple Service Providers. See issue https://github.com/slimphp/Slim/issues/1250.
silentworks/Twig-View,juliangut/Twig-View,akrabat/Twig-View,Swader/Twig-View,piotr-cz/Twig-View,Swader/Twig-View,silentworks/Twig-View,slimphp/Twig-View,akrabat/Twig-View,slimphp/Twig-View,piotr-cz/Twig-View,juliangut/Twig-View