Update Worker.php

add worker.php swoole  event support

Worker.php

@@ -425,7 +425,8 @@ class Worker
      */
     protected static $_availableEventLoops = array(
         'libevent' => '\Workerman\Events\Libevent',
-        'event'    => '\Workerman\Events\Event'
+        'event'    => '\Workerman\Events\Event',
+	'swoole'   => '\Workerman\Events\Swoole'
     );
 
     /**