Create Github Actions

[KrisThielemans]

We need to migrate away from Travis sadly.

caching

• general doc: https://docs.github.com/en/actions/guides/caching-dependencies-to-speed-up-workflows
• ccache: https://cristianadam.eu/20200113/speeding-up-c-plus-plus-github-actions-using-ccache/
• a precanned action based on the above: https://github.com/hendrikmuhs/ccache-action

secrets

@casperdcl wrote in Nov20

Migrating saved env vars to a different provider seems the main pain point. Created this to help. Tested & works: https://github.com/casperdcl/ci-env-migrate

The advantage of github actions is that you can easily set up self-hosted runners with e.g. matlab, vis https://github.com/AMYPAD/SPM12/blob/2bd4fc4907834df0d22968dfd94d509ed16efa50/.github/workflows/test.yml#L23.

[KrisThielemans]

there's far more to do here, so reopening

[KrisThielemans]

caching done. Now a matrix with different builds

[KrisThielemans]

re-opening as still lots to do.

• test more configurations without exponentially increasing the number of jobs
• add docker creating/builds
• attempt MacOS builds
• attempt Windows builds

[paskino]

I'm more in favour of closing this issue and opening new ones to address the TODO list you have here

• test more configurations without exponentially increasing the number of jobs
• add docker creating/builds
• attempt MacOS builds
• attempt Windows builds

I will probably create a project with all this stuff.

[KrisThielemans]

sure. as you prefer