Update django-redis to 4.11.0

[pyup-bot]

This PR updates django-redis from 4.10.0 to 4.11.0.

Changelog

4.11.0

--------------

Date: 2019-12-13

- Removed support for Python 2.7 and 3.4.
- Removed support for Django 2.0 and 2.1.
- Added support for Python 3.8.
- Added support for Django 2.2 and 3.0.
- Changed msgpack-python soft dependency to msgpack.
- Fixed ``.touch()`` method for sharded client.
- Fixed prefix escaping for the sharded client.
- Fixed ``.add()`` method to return a bool.

Links

• PyPI: https://pypi.org/project/django-redis
• Changelog: https://pyup.io/changelogs/django-redis/
• Repo: https://github.com/niwibe/django-redis

[pyup-bot]

Closing this in favor of #581