Adding middleware registration

Author: lucadegasperi

src/OAuth2ServerServiceProvider.php

@@ -166,5 +166,6 @@ private function bootFilters()
         $this->app['router']->filter('check-authorization-params', 'LucaDegasperi\OAuth2Server\Filters\CheckAuthCodeRequestFilter');
         $this->app['router']->filter('oauth', 'LucaDegasperi\OAuth2Server\Filters\OAuthFilter');
         $this->app['router']->filter('oauth-owner', 'LucaDegasperi\OAuth2Server\Filters\OAuthOwnerFilter');
+        $this->app['router']->middleware('LucaDegasperi\OAuth2Server\Middleware\OAuthExceptionHandlerMiddleware');
     }
 }