Update CI testing - github actions

[schwehr]

The Travis CI build is not working great and github actions work pretty well for Linux, Mac, and Windows.

Would be nice to have:

• Test coverage reporting
• asan/msan runs. Would be nice to run over all the tests and a good range of messages in a couple MB blob of AIS
• clang static analyzer (CSA)
• cppcheck probably with --enable=all --inconclusive
• codespell
• What other checks can be done? (e.g. look in the proj, libgeos, and gdal workflows below)

Notes:

• An initial PR that only does the bare minimum of build and test is a totally fine place to start
• Only testing the CMake setup would be ok. Consider dropping the other build systems
• Probably only need to do one version of C++ (probably C++20)

These could be starting points:

• https://github.com/OSGeo/shapelib/blob/master/.github/workflows/main.yml
• https://github.com/OSGeo/PROJ/tree/master/.github/workflows
• https://github.com/OSGeo/gdal/tree/master/.github/workflows
• https://github.com/libgeos/geos/blob/main/.github/workflows/ci.yml

See also:

• https://twitter.com/kurtschwehr/status/1434889703929511940

[schwehr]

Thanks to Gino for point out:

https://github.com/marketplace/actions/install-gcc

[schwehr]

https://github.com/schwehr/libais/commit/a11495b3e61205a20025ef4ee3de1be6c3b98570 added github actions