Django 2.0 adoption

- woo

Closes #72
2 jobs for 72-django-two-dot-oh in 1 minute and 27 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Test
passed whats-open-py3.5 #4071

00:01:25

passed whats-open-py3.6 #4072

00:01:26