Start writing web server

If you run the server, it creates one test user in the database, so the only things you can really do currently are `GET /hello` and `GET /user/1`.
Cool! This looks like a good balance between the flask debug server and nginx.

I should point out (in case you weren't thinking about it) that sqlalchemy is blocking, which will block tornado, but I'm not expecting any scalability issues! :shipit: