Author Serializer Return Relations

[derekdowling]

When getting data from the serializer it should return the following relation fields on successful login:

"following": []
"friends": []
"pending": []
"requests": []

Each of which is a potentially empty list of CachedAuthors. The models are already hooked up the serializers just need to be dealt with.

[xkb]

Another note on this, I'm expecting these fields to be always set and returned via GET /author/login and GET /author/:id

pending and following should be empty lists when GET /author/:id is on a foreign author or an author that isn't the one making the request. Does that make sense?

[lanre-ade]

So basically return friends, following etc only when author is requesting their own information?

[xkb]

friends should always be returned regardless of requester.

[derekdowling]

Closed by #171