Add Authors API and update Author API

[kaynzhel]

• based on project reqs (link is on this repo's readme)
• Added views, serializers, and then tested them
• Had to update Follow, Follower, and Inbox tests/serializer since they also need to serialize a given author. Since the AuthorSerializer is updated, we need to update how we're handling it here as well.
• Updated the author_id check in PostsList component with the updated id field (it was initially just uuid, now id returns an id url)
• NOTE: I didn't do post method for the AuthorView as to not interfere with current user story As an author, I want to be able to use my web-browser to manage my profile #24

TEST

• Feel free to test the web app to QA

POSTMAN

Single Author	Authors

[rmgutierrez]

lgtm!