Install regexes.yaml correctly

This fixes #209, the annoying issue where user_agent_parser
fails at runtime because it can't find regexes.yaml or regexes.json.

Seems to work for:
* `python setup.py develop` in ua-parser itself (as before)
* `python setup.py install` in ua-parser itself (as before)
* `python setup.py install` in some *other* package that
  depends on ua-parser
* `pip install ua-parser`