Added multichannels and a simple channel-based bus

src/Interop/Channel/ChannelInterface.php

@@ -20,10 +20,10 @@ interface ChannelInterface
     public function receive();
 
     /**
-     * Send a frame of data
+     * Send a frame of data, returns true on success
      *
      * @param mixed $data
-     * @return void
+     * @return bool
      */
-    public function send($data);
+    public function send($data):bool;
 }