Removed django-cacheops dependency

Removed Cacheops dependency
---------------------------

We removed one of our dependency named django-cacheops. It was unly used in a few places,
and not playing nice with other dependencies.

You can safely remove this dependency in your environment with ``pip uninstall django-cacheops`` if you're
not using docker.

You can also safely remove any ``CACHEOPS_ENABLED`` setting from your environment file.