Allows users to authenticate using a token
Automatically creates Auth Tokens for new users
Fixes TestWithMongo

For some reason saving a string to gridfs no longer works, so we have to send a
file-like object.
Brings fix from f839d5b to the `reset_gridfs_collection` script
Creates a page with the user's API Token

This also includes a short explanation on how to use it to login.
Merge pull request #104 from flavioamieiro/feature/token_auth

Allows users to authenticate using a Token