Skipping dispatch if an MvcEvent#getResult() is not null (fixes tests)

Author: Ocramius

src/MiddlewareListener.php

@@ -45,6 +45,10 @@ public function attach(EventManagerInterface $events, $priority = 1)
      */
     public function onDispatch(MvcEvent $event)
     {
+        if (null !== $event->getResult()) {
+            return;
+        }
+
         $routeMatch = $event->getRouteMatch();
         $middleware = $routeMatch->getParam('middleware', false);
         if (false === $middleware) {