Add support for Django 1.11 and 2.0

[epicserve]

I'm currently getting an error when trying to use Django 2.0.

[mjhea0]

Can you post the error?

[epicserve]

@mjhea0, It seems to work on my Django 1.11 branch and my Django 2.0 branch is broke right now in my project so, you can just close this issue if you want. However, it might be a good idea to add Django 1.11 and 2.0 to your tox.ini.

[koleror]

Django 1.11 was added to the supported list. Do you have the error with django 2.0?
I'll have a look when I get some time.

[bblanchon]

I can confirm that this project works fine with Django 3.0.10. 👍