Factor out a Client class, separate Entity classes

This also changes the client API slightly (post vs posts, etc).
Merge branch 'separate-client-class' of https://github.com/nateberkopec/hunting_season into nateberkopec-separate-client-class
Allow for making multiple and differing calls to 'comments', 'votes' via a Post
Ensuring config (namely token) is passed in with each API call