Feature/add composition section

Typically, 

`before_filter :authenticate_user!`

checks to make sure you're already authenticated. If you're not, it will redirect you to a sign-in page.

You can test the security of your routes by recreating the `POST` to the respective endpoint with `curl`. You'll pass some expected data and a csrf_token (just inspect any form and watch the payload that it passes) and you'll see what a submission looks like.

RailsAdmin most likely checks that you're logged in for any actions, but this controller is outside of RailsAdmin (at least it appears to be). At the moment, it's possible to hit ProductionController#create without being logged in.