Django 3.1 is currently not tested but [is released](https://docs.djangoproject.com/en/3.1/releases/3.1/). https://github.com/django-dbbackup/django-dbbackup/blob/4ad864b2ae288ae1155c1bb2b2215121379c7223/tox.ini#L21 Relates to #353
