Move testing from Travis CI to GitHub Actions

[hugovk]

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, let's do the same.

We already have tests on GHA, just missing sending coverage to Codecov. Earlier it was tricky to do, but Codecov now have an action for this; added here. Done in #480.

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We'll need to move deployment from Travis to GHA. We already got it working for another Jazzband project, but I'll do it in a followup PR.

So this one reduces the Travis testing to a single job.

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This also fixes a pytest warning: Done in #480.

[codecov]

Codecov Report

Merging #479 (5131ea2) into master (22c88de) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #479   +/-   ##
=======================================
  Coverage   90.66%   90.66%           
=======================================
  Files          28       28           
  Lines        2613     2613           
=======================================
  Hits         2369     2369           
  Misses        244      244           

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[claudep]

I'm not so thrilled to add even more dependencies on Github. I don't see Travis limitation a problem for our usage, do you?

[hugovk]

Unfortunately yes, others and I are seeing big problems with Travis CI.

• https://travis-ci.community/t/contradictory-information-in-the-ui-on-whether-credits-are-replenished-on-the-free-plan/10518
• https://travis-ci.community/t/extremely-poor-official-communication-of-the-org-shutdown/10568
• https://travis-ci.community/t/org-com-migration-unexpectedly-comes-with-a-plan-change-for-oss-what-exactly-is-the-new-deal/10567
• https://travis-ci.community/t/how-to-migrate-from-org-to-com-in-the-light-of-org-shutting-down/10566
• https://travis-ci.community/t/builds-hang-in-queued-state/10250
• https://travis-ci.community/t/builds-taking-1hr-to-start/10560
• https://travis-ci.community/t/my-build-is-stuck-in-waiting-to-be-queued-phase/10533
• https://travis-ci.community/t/build-delays-for-open-source-project/10272
• https://travis-ci.community/t/exceeded-user-count-unlimited/10484

First, travis-ci.org has been really slow (maybe we were lucky just now, on a Saturday) with long delays of sometimes up to an hour before jobs begin.

That's because they've been moving resources from .org to travis-ci.com, and everything will need to be moved to travis-ci.com by the end of the year, when .org will be closed down.

• https://docs.travis-ci.com/user/migrate/open-source-repository-migration

Second, there's a new credit-based pricing model on .com. They give a 10k-credit free trial, enough for 1k Linux minutes. When that expires they encourage you to buy a plan or ask to be on some new OSS plan, where if the project meets the requirements, they will evaluate how many credits the project can have. It's not clear if this renews monthly or if the process must be repeated when the credits expire.

• https://blog.travis-ci.com/2020-11-02-travis-ci-new-billing

I've applied for credits for another project but not got very far yet.

• https://twitter.com/hugovk/status/1326935425903185920

Some more info here:

• TravisCI price model change zopefoundation/meta#38

[claudep]

Thanks so much for this detailed report. I would not rush however in changing things, firstly because tablib does not see so much activity (we can affort waiting 1-2 hours for tests) and Travis may react to the Web feedback at some point.

[hugovk]

Okay, let's wait a bit.

I'll make a new PR with the first commit (GHA coverage) and third (fix pytest warning), they're still useful now. Edit: #480.

[hugovk]

(Rebased after merging subset #480.)

[hugovk]

All Jazzband repos need porting over to GHA:

• Should we disable travis? help#206

[jezdez]

The alternatives of course are Azure, GitLab, Circle CI and a few others. Given the fact that GitHub Actions are designed to allow self-hosted test runners I'd say the risk of lock-in is manageable compared to the added benefits of direct integration in the GitHub development workflow.

Luckily there is https://github.com/ymyzk/tox-gh-actions so the migration of all projects should be relatively straight-forward.