Remove body parser

I don’t know enough to know when this is useful, but right now it’s
messing up the PUT & POST payloads that go to the Rails app.
Get tests passing again by removing nag-section

This code is no longer used
Merge branch 'master' into trainee-accounts
Get all the tests passing

Reworked the use of policies in active_model_serializers so we could access
the current_user and determine demo/not-demo based on whether the user was logged in or not.