Return the subscription ID

Author: JamesMGreene

lib/ddp-client.js

@@ -329,6 +329,8 @@ DDPClient.prototype.subscribe = function(name, params, callback) {
     self._callbacks[id] = callback;
 
   self._send({msg: 'sub', id: id, name: name, params: params});
+
+  return id;
 };
 
 DDPClient.prototype.unsubscribe = function(id) {