Migrate from TravisCI to GitHub Actions

[markets]

TravisCI worked really well for years, but after all changes they made in latest times, also for OSS projects... time to say 👋🏼

GH Actions are really cool and flexible ✨

Some interesting articles about Travis:

• https://daniel.haxx.se/blog/2021/06/14/bye-bye-travis-ci/
• https://www.jeffgeerling.com/blog/2020/travis-cis-new-pricing-plan-threw-wrench-my-open-source-works

Things to be considered:

• We need Postgresql 9.4
• We'd like to keep CodeClimate Test Coverage reporting

Help much appreciated! 🤝

[sauloperez]

Definitely, OFN started this migration recently as well. We can copy its configuration :point_right: https://github.com/openfoodfoundation/openfoodnetwork/blob/master/.github/workflows/build.yml, although Github's guides are pretty complete and we shouldn't have any problem.

Although I also wanted to use that

We'd like to keep CodeClimate Test Coverage reporting

We ended up using https://codecov.io/ and so far so good. We use it as well for other Coopdevs projects.

We need Postgresql 9.4

That looks reaaaally old :see_no_evil: We should probably plan an upgrade.

[markets]

@sauloperez couple of comments:

1. About the CodeClimate thing, I just see there is also an official GH Action app for CodeClimate in the marketplace, so we can keep both report: Quality and Coverage (not sure if CodeCov reports also Quality). So, I'd stick with CodeClimate for now.

2. About Postgresql version, 100% agree, we should plan an upgrade sooner than later, but I'd do it separately from this migration. This will need some coordination with Infra and probably a rebuilt of the structure.sql file in the repo.

Thanks for the OFN example, we can start from there!