Move middleware.

app/Http/Kernel.php

@@ -11,7 +11,7 @@ class Kernel extends HttpKernel {
 	 * @var array
 	 */
 	protected $middleware = [
-		'App\Http\Middleware\UnderMaintenance',
+		'Illuminate\Foundation\Http\Middleware\UnderMaintenance',
 		'Illuminate\Cookie\Middleware\EncryptCookies',
 		'Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse',
 		'Illuminate\Session\Middleware\StartSession',

app/Http/Middleware/UnderMaintenance.php

-<?php namespace App\Http\Middleware;
-
-use Closure;
-use Illuminate\Http\Response;
-use Illuminate\Contracts\Routing\Middleware;
-use Illuminate\Contracts\Foundation\Application;
-
-class UnderMaintenance implements Middleware {
-
-	/**
-	 * The application implementation.
-	 *
-	 * @var Application
-	 */
-	protected $app;
-
-	/**
-	 * Create a new filter instance.
-	 *
-	 * @param  Application  $app
-	 * @return void
-	 */
-	public function __construct(Application $app)
-	{
-		$this->app = $app;
-	}
-
-	/**
-	 * Handle an incoming request.
-	 *
-	 * @param  \Illuminate\Http\Request  $request
-	 * @param  \Closure  $next
-	 * @return mixed
-	 */
-	public function handle($request, Closure $next)
-	{
-		if ($this->app->isDownForMaintenance())
-		{
-			return new Response('Be right back!', 503);
-		}
-
-		return $next($request);
-	}
-
-}

resources/views/framework/maintenance.php

+Be right back!