Update django-environ to 0.6.0

[pyup-bot]

This PR updates django-environ from 0.4.5 to 0.6.0.

Changelog

0.6.0

----------------------------
Added
+++++
- Python 3.9, 3.10 and pypy 3.7 are now supported
- Django 3.1 and 3.2 are now supported
- Added missed classifiers to ``setup.py``
- Accept Python 3.6 path-like objects for ``read_env``

Fixed
+++++
- Fixed various code linting errors
- Fixed typos in the documentation
- Added missed files to the package contents
- Fixed ``db_url_config`` to work the same for all postgres-like schemes

Changed
+++++++
- Refactor tests to use pytest and follow DRY
- Moved CI to GitHub Actions
- Restructuring of project documentation
- Build and test package documentation as a part of CI pipeline
- Build and test package distribution as a part of CI pipeline
- Check ``MANIFEST.in`` in a source package for completeness as a part of CI pipeline
- Added ``pytest`` and ``coverage[toml]`` to setuptools' ``extras_require``

0.5.0

--------------------------
Added
+++++
- Support for Django 2.1 & 2.2
- Added tox.ini targets
- Added secure redis backend URLs via ``rediss://``
- Add ``cast=str`` to ``str()`` method

Fixed
+++++
- Fixed misspelling in the documentation

Changed
+++++++
- Validate empty cache url and invalid cache schema
- Set ``long_description_content_type`` in setup
- Improved Django 1.11 database configuration support

Links

• PyPI: https://pypi.org/project/django-environ
• Changelog: https://pyup.io/changelogs/django-environ/
• Docs: https://django-environ.readthedocs.org

[pyup-bot]

Closing this in favor of #424