Update .travis.yml

Added 0.10.4
[front] Attach socket.id to outgoing API server messages. Incoming messages from the API server will now attempt to be relayed back to the front-end socket with matching id.
[api] Echo back all incoming socket messages ( for now )
[api] Incoming messages are now appended with front server information ( host / unique id ). Incoming messages are now routed to an `engine.send_message` stub. Current stub echos back message.
[public] Added default socket message to homepage.
[front] [api] [minor] Added some error handlers