Lint YAML and Python files on CI

[MattiSG]

OpenFisca-France has tests to automatically lint YAML and Python files.

I believe the publishing process is already part of the OpenFisca Country Template suggestions, and that maintaining consistent quality and syntax is a meaningful way to ease contribution.

I thus suggest importing these tests, alongside any other improvements made to the testing procedure, to the Country Template (probably toning down a bit the tongue-in-cheek phrasings 😉).

Opinions welcome @openfisca/international-contrib!

[HAEKADI]

@MattiSG Should we only add the linting job, or restructure the entire CircleCI configuration like we did with OpenFisca France here?

The restructuring would include amongst other things:

• Separating the install from the build
• Separating the buildand the test
• Using openfisca test instead of make test, which does check for syntax errors and does some linting as well
• Adding a separate job which lints Python and YAML files
• Changing the job dependencies in the workflow

[MattiSG]

Yes, and we should also switch to GitHub Actions as agreed on openfisca/openfisca-core#1030 😉
This issue is only about adding linting. It can be closed alongside others if a larger PR is open on that topic 🙂