Update pytest for testing extra (Fixes #1365)

[rbpatt2019]

Update pytest and plugins to most recent version for testing extra.

Contributor Checklist

• I have broken down my PR scope into the following TODO tasks
  • Update pytest to 6.0.1
  • Update pytest-sugar to 0.9.4
  • Update pytest-mock to 3.2.0 for python 3 only!

optionals

• I have added entry in the CHANGELOG.md

[rbpatt2019]

@alexcjohnson Turns it out it isn't as simple as just upgrading pytest! Several tests now fail, all related to the following error message:

/home/circleci/dash/venv/lib/python3.6/site-packages/pytest_sugar.py:214: PytestDeprecationWarning:

The TerminalReporter.writer attribute is deprecated, use TerminalReporter._tw instead at your own risk.
See https://docs.pytest.org/en/stable/deprecations.html#terminalreporter-writer for more information.

pytest 6.0.0 changed the way they handle deprecations - they always call as errors now, as the affected features will be removed in 6.1.0. Seems pytest-sugar uses one of these affected features (https://docs.pytest.org/en/stable/changelog.html#id19 under Terminal Writer). I'll play with updating pytest-sugar locally, and see how that goes. If it's an issue on their end, I'll raise one there!

[rbpatt2019]

That did it! The deprecation warning was fixed by updating pytest-sugar to 0.9.4. I also split pytest-mock into 2 requirements: 3.2.0 for python >= 3 and 2.0.0 for python == 2.7, which allows users to get the most up-to-date pytest -mock for their version.

[alexcjohnson]

Fantastic! Nice job figuring out pytest-sugar and pytest-mock. I think this does warrant a brief changelog entry since unlike a lot of dep bumps this impacts users (like yourself 😄), then we're ready to go!

[rbpatt2019]

That should do it! Let me know if there's anything else - always happy to contribute :)

[alexcjohnson]

Perfect, thanks! 💃