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`.
Because I'm a sucker for code golf:

```python
re.sub(r"_(.)?", lambda m: (m.group(1) or "").upper(), s)
```

or, if don't care to strip trailing underscores:

```python
re.sub(r"_(.)", lambda m: m.group(1).upper(), s)
```

[Based on underscore.string's camelize function](https://github.com/epeli/underscore.string/blob/52be74cf2c8ef2c9a2164c72e71dacf955978d88/lib/underscore.string.js#L339).