make API more RESTful

[keggsmurph21]

• [ ] some sort of authentication scheme
• [ ] should have an endpoint for GET/POST as well as socket.io connections
  • [ ] messages
  • [ ] lobby
  • [ ] admin
  • [ ] play
  • [ ] account management/creation

[keggsmurph21]

• [ ] handle errors more gracefully (in particular with lobby and admin) ... that means return sane status codes & messages when operations go wrong, know which ones should be displayed to the client and which shouldn't