chore(controller): update django-cors-headers to 1.0.0

See https://github.com/ottoyiu/django-cors-headers/releases/tag/1.0.0
Merge pull request #2785 from mboersma/update-cors-headers

chore(controller): update django-cors-headers to 1.0.0
docs(disable-registration): adds documentation on how to disable user registration