This commit adds GitHub Actions configuration, running tests on
pull-requests and master push changes.
This change is meant to be a first-pass at our evolving CI processes.
- Tests run in parallel per language for speed and isolation
- Test matrix is composed by a string list of languages and versions
- `setup-${language}` actions are preferred over base (and changing)
versions from `ubuntu-latest` operating system
A few caveats with the current setup:
- Only tests on Ubuntu (no FreeBSD or Alpine)
- Unpriviledged tests only
- No core dumps available on failure
