Travis seems to be going away from supporting Open Source Software for
free and their proceedure to gaining free tokens is getting harder and
hander to find for each year that passes. Remove Travis CI integration
and migrate the coverage reporting previously provided by the Travis
build over to the GitHub Actions.
Based on docker and github actions
Builds a docker image for each commit as well as the lua lib mod
Builds the master branch of subspace_storage for use with the tests
Tests are based on latest stable factorio branch