Improve API tests

[MarkGalloway]

The tests have very low coverage, and many aren't really testing much.

I would rather see tests like this:

• Create a post using PUT -- Verify only one post is created -- Fetch the post using GET, verify the fields -- Fetch the post using POST, verify the fields
• Update a post using PUT -- Verify the old post with {ID} still exists -- Verify only one post {ID} still exists -- Fetch the post using GET, verify the fields -- Fetch the post using POST, verify the fields

etc...

[MarkGalloway]

This is really important, so I will start on this and fix all of the (~8) failing tests.

[MarkGalloway]

I've fixed all of the Posts API failing tests.

There are still failing Friends API tests. It might be the actual views that are broken since @Tamarabyte changed the models

[MarkGalloway]

Improved enough for now.