Django 2.0 Compatibility

[4word]

Pre-opening this issue, will be working on compat with 2.0 over the next couple weeks since its in the Django master branch now. Will link the branch once its ready and will open a PR when 2.0 goes into beta.

[JBKahn]

awesome, thanks

[Braintelligence]

So how far along is this? Also it would be awesome if you'd incorporate Django version requirements into the README, since it doesn't say anything about not being compatible with Django 2.0+.

[JBKahn]

It's done! We've been using it in production basically since Django 2.0 came out. I'll update the docs!