Included Django-Rest-Framework Auth URLs
Tidied up a coment.
Stubbed a simple API for the Game Boards.

Includes URLs at `/api/boards/` and `/api/boards/:board-pk/`.
Created a simple seralizer.

This serializer only works one-way, for now. It will take a Board and
convert it into a Django-Rest-Framework serialized object. It includes
the `pk` as a read-only field.