WIP Role requests

I added the first 2 commits in another PR: #66 

I have tried to create role requests for new authors that are added when content is updated.  I've not yet added any other user fields like editors or publishers.  No emails are sent yet when role requests are created.  But there is a url for posting the response of a role request `/roles/{id}@draft.json`, the expected post data is either `{response: "accept"}` or `{response: "reject"}`.