CI Improvements

[samypr100]

Summary of changes

1. Updated the CI as part of Fix CI: replace Travis CI. #2641 to use full matrix for Linux/OSX as well as non-eol python versions
2. Cherry picked c04a30f to get tests working
3. Fixed some tox issues preventing tox from working due to v4 changes discussed here
4. Adjusted linting to use pylint version where it used to pass (back in travis CI days), if we want to use latest and correct the linting issues as they come we can revert the pylint version lock

I realized a bit too late that you were already working on #2920, so I apologize if you think this seems duplicative.

🔗 to workflows on my fork for this branch

Failing CI Issues Left

1. pycodestyle doesn't seem to pass in any version I tested, so maybe that should be a separate PR?

[benoitc]

yes let's fix pycodestyle errors apart. thanks a lot for your PR!

[johnthagen]

@benoitc In order to keep the CI green, you could set all of the GitHub Actions checks as required in order to allow a PR to be merged:

• https://docs.codemagic.io/yaml-notification/github-checks/
• https://stackoverflow.com/a/69206611

As the administrator of the repo you can always still override them, but this can help from accidentally merging a PR where one of the checks fail.

[samypr100]

@johnthagen Good suggestion, I've attached some Screenshots of how it would look like if its desired to go that route