Update django-test-plus to 2.2.0

[pyup-bot]

This PR updates django-test-plus from 1.0.21 to 2.2.0.

Changelog

2.2.0

- Add support for Django 3.2.

2.1.1

- Add official support for Python 3.9.

2.0.1

- Make assertLoginRequired work for pytest tp fixture.

2.0.0

- Drops Python 2.7, 3.4, and pypy and Django 1.11 support.
- Add Django 3.1 support.

1.4.0

- Added Django 3.0 support
- Misc dependency updates

1.3.1

- Made `make_user` and `get_instance` class based methods, so they can be used
 in `setupUpTestData`. Thanks avelis for the report.

1.3.0

- Add `tp_api` pytest fixture.

1.2.0

- Add optional `msg` argument to assertEqual method. Thanks davitovmasyan.

1.1.1

- Fix premature loading of Django settings under pytest

1.1.0

- Added real pytest fixture support! 
- Stopped testing support below Django 1.11.x. django-test-plus should probably continue to work for a long time, but Django 1.11 is the only pre-2.x version that is still supported so all we are going to worry about.
- Moved README and docs to Markdown

version 1.0.22 - January 9th, 2018

- Fix bug where we did not pass data dictionary to RequestFactory.get() properly

Links

• PyPI: https://pypi.org/project/django-test-plus
• Changelog: https://pyup.io/changelogs/django-test-plus/
• Repo: https://github.com/revsys/django-test-plus/