ci: add github CI to replace travis CI

[mariajgrimaldi]

Description

This migrates Travis CI configuration to Github actions. This approach was discussed here as a consequence of Travis CI changing support for open source projects.

Concerns

• Should we keep the Travis CI configuration?
• Which python version was being used for the quality checks?
• On which events should we trigger testing?

[mariajgrimaldi]

Hey! @jschneier

I think Github Actions are not enabled

[jschneier]

@mariajgrimaldi that isn't what I see but it's not clear to me why it isn't running.

[jschneier]

@mariajgrimaldi for your questions

1. You can also ahead and delete the Travis stuff
2. For linting, it would be ideal if the minimum version of Python was used but I don't think it overly matters
3. Tests should run on PR open and PR update (push to PR). It should also run against trunk after merging.

[mariajgrimaldi]

Thanks for the response @jschneier! I used python 3.6 for this restriction: https://github.com/jschneier/django-storages/blob/master/tox.ini#L55

Also, do you know why checks are not running? They do here: https://github.com/mariajgrimaldi/django-storages/pull/1/checks

Is it because it is from a fork?

[jschneier]

Unclear, I think because I didn't "set it up" myself. I'm going to commit this and see what happens.

[jschneier]

@mariajgrimaldi yup! Looks like it's working!

https://github.com/jschneier/django-storages/actions/runs/1209946412

[mariajgrimaldi]

excellent!! @jschneier, thanks for the help. Can you make a release with these changes?

[natabene]

@jschneier Just checking if you could look into doing a release with this changes some time soon. I would greatly appreciate, as it would really help our Django upgrade project for the Open edX Platform.