message: Assign uid to hello message
  Hello is the only message without user id and it can cause issues
diff: @@ -54,6 +54,7 @@ function SocketBot(configuration) {
  var uid = message.user;
  if (!uid) {
  uid = guid();
  + message.user = uid;
  bot.send({
  type: 'hello',
  user: uid,
  