Moved all the fields to the root.

At the start, I thought that the fields would be more complex but after working
with them for a while, it turns out that the code was a lot simpler than
expected so I moved it all to a single file in the root and removed the model.
Start of very simple testing setup.

We want our application to be well tested in the future, this is the start of
that.
Convert the index to CBV.

As the utils were deleted and the json response was integrated into our CBVs,
DRY demanded that we moved the API index view into a CBV.
Some smaller tidiness changes.