Migrate to GitHub actions

[BillyAutrey]

• Removes .travis.yml.
• Adds build-test.yml and publish.yml, using standard configs/rules from playframework/.github.
• Changes checks and mergify rules to use GitHub checks instead of Travis rules/builds.

[mkurz]

Except for the main play repo we never ran nightly builds. And there we ran them because we do enable additional jobs which take a while, so its better to no have them run for each pull request.

I suggest to remove the schedule section here and replace it with

  push:
    branches:
      - main # Check main branch after merge

instead (so the build will be triggered after merge again, so we should be pretty safe I guess)

[BillyAutrey]

Okay, makes sense. I was mainly concerned with placing the Travis badge, and wasn't sure which approach to take to get valid statuses from main.

[mkurz]

You mean the GHA badge? I think it just looks at the last run and that's the status it shows.

[BillyAutrey]

Ah! Well that's easier then. Master runs would fix this, I'll change it.

[mkurz]

Thanks! A couple of things needs to be addressed.

[mkurz]

This is not the only thing that needs to be changed in the mergify conf.
You can actually just copy the conf from twirl: https://github.com/playframework/twirl/blob/main/.mergify.yml
As you can see it adds queue_rules add the top and then uses this queue in actions. The merge action is deprecated AFAIK.

[mkurz]

One more thing: We should also add branches:... like here.
This way snapshots get published each time a pull request gets merged. That's quite nice to have. (akka does the same btw)

[mkurz]

Great!