Update for composer branch

extensions/embed/bootstrap.php

@@ -1,5 +1,17 @@
 <?php
 
-require __DIR__.'/vendor/autoload.php';
+/*
+ * This file is part of Flarum.
+ *
+ * (c) Toby Zerner <toby.zerner@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
 
-return 'Flarum\Embed\Extension';
+use Flarum\Embed\Listener;
+use Illuminate\Contracts\Events\Dispatcher;
+
+return function (Dispatcher $events) {
+    $events->subscribe(Listener\AddEmbedRoute::class);
+};