fix new peer object

lib/peer.js

@@ -6,7 +6,7 @@ function Peer(id, options) {
     options = id;
     id = undefined;
   }
-  if (!(this instanceof Peer)) return new Peer(options);
+  if (!(this instanceof Peer)) return new Peer(id, options);
   EventEmitter.call(this);
 
   options = util.extend({