exception on Windows: NotImplementedError: c

[pcoccoli]

Reported by user on Windows.

File "C:\Users\redacted\pyenv\redacted\lib\site-packages\firepit\__init__.py", line 30, in get_storage
   raise NotImplementedError(url.scheme)
NotImplementedError: c

I think what happened here is that a Windows path was passed in as the url to get_storage. The urlparse looks at it and thinks c is the "scheme" but we only support "" or "postgresql". We could add some code to try and detect a Windows path and then skip urlparse.