Shahn/misc

I would appreciate a code review. It's mostly cleaning things up a bit.

Especially https://github.com/zalora/sproxy-web/commit/ee0bbad64d055e6268775e933cb8dd4f690befd3 is problematic since it serves source code files. In production we do fall back to serving static files from the installation directory (I think), so it should be fine. But I would feel much better if we could limit the serving of static files to the static directory. I just didn't manage to do this.