Migrate to GitHub Actions.

[jezdez]

Travis CI has a new pricing model which places limits on open source.

• https://blog.travis-ci.com/2020-11-02-travis-ci-new-billing
• https://www.jeffgeerling.com/blog/2020/travis-cis-new-pricing-plan-threw-wrench-my-open-source-works

Many projects are moving to GitHub Actions instead, including Jazzband projects:

• https://github.com/orgs/jazzband/projects/1
• Should we disable travis? help#206

This is based on jazzband/contextlib2#26.

It drops support for Python 3.5 because GitHub Actions doesn't fully support them. It's EOL anyway.

Python 3.9 support is also added.

This also relates to #343 in that it enables the release workflow mentioned there with @dokterbob as proejct lead. The version is deducted from the last git tag automatically using setuptools_scm.

TODO:

• @jezdez to add JAZZBAND_RELEASE_KEY to the repo secrets.

[codecov]

Codecov Report

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The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #358   +/-   ##
=========================================
  Coverage          ?   86.02%           
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  Files             ?       16           
  Lines             ?     1302           
  Branches          ?      137           
=========================================
  Hits              ?     1120           
  Misses            ?      135           
  Partials          ?       47           

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[jezdez]

@claudep Hey, I've added you as well since you've done some work on this library and I want to make sure we move this along. This is fully in line what all the other Jazzband projects have done FWIW.

[claudep]

Sorry, I'm no longer active on django-newsletter.

[jezdez]

Sorry, I'm no longer active on django-newsletter.

Got it, thank you!

[jezdez]

@aleksihakli Apologies for pulling you into this, I want to move ahead with this pull request and your review would be much appreciated!

[aleksihakli]

Hey @jezdez! I've been a bit busy but I'll review this today. Feel free to ping me via mail or on GitHub in case you need any help, I'll happily assist if I have the bandwidth :)

[jezdez]

Hey @jezdez! I've been a bit busy but I'll review this today. Feel free to ping me via mail or on GitHub in case you need any help, I'll happily assist if I have the bandwidth :)

Understood and no problem, thank you for getting back to me :)

[aleksihakli]

LGTM! setup.py package classifiers should probably also include Python 3.9 and possibly Django version classifiers?