Moves the RouteResultObserverInterface back to the Expressive namespace

This patch moves the `RouteResultObserverInterface` into the `Zend\Expressive`
namespace. Since it is triggered by `Application`, it is an application-level
responsibility, not the router's.

Since the class names do not conflict, this can lead to an immediate deprecation
of the original interface in the zend-expressive-router package. However,
zend-expressive-zendviewrenderer will need updates so that it fulfills the new
interface via its `UrlHelper` instance.

Author: weierophinney

src/Application.php

@@ -176,19 +176,19 @@ public function any($path, $middleware, $name = null)
     /**
      * Attach a route result observer.
      *
-     * @param Router\RouteResultObserverInterface $observer
+     * @param RouteResultObserverInterface $observer
      */
-    public function attachRouteResultObserver(Router\RouteResultObserverInterface $observer)
+    public function attachRouteResultObserver(RouteResultObserverInterface $observer)
     {
         $this->routeResultObservers[] = $observer;
     }
 
     /**
      * Detach a route result observer.
      *
-     * @param Router\RouteResultObserverInterface $observer
+     * @param RouteResultObserverInterface $observer
      */
-    public function detachRouteResultObserver(Router\RouteResultObserverInterface $observer)
+    public function detachRouteResultObserver(RouteResultObserverInterface $observer)
     {
         if (false === ($index = array_search($observer, $this->routeResultObservers, true))) {
             return;

src/RouteResultObserverInterface.php

@@ -0,0 +1,22 @@
+<?php
+/**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @see       https://github.com/zendframework/zend-expressive for the canonical source repository
+ * @copyright Copyright (c) 2015 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   https://github.com/zendframework/zend-expressive/blob/master/LICENSE.md New BSD License
+ */
+
+namespace Zend\Expressive;
+
+use Zend\Expressive\Router\RouteResult;
+
+interface RouteResultObserverInterface
+{
+    /**
+     * Observe a route result.
+     *
+     * @param RouteResult $result
+     */
+    public function update(RouteResult $result);
+}

test/RouteMiddlewareTest.php

@@ -16,7 +16,7 @@
 use Zend\Diactoros\ServerRequest;
 use Zend\Expressive\Application;
 use Zend\Expressive\Router\RouteResult;
-use Zend\Expressive\Router\RouteResultObserverInterface;
+use Zend\Expressive\RouteResultObserverInterface;
 use Zend\Expressive\Router\RouterInterface;
 
 class RouteMiddlewareTest extends TestCase