travis-ci.org has sadly backed down from the "Testing your open source projects will always be free!" they are still advertising on their page and forcing everyone still wanting to use the service to migrate to travis-ci.com which doesn't have a similar free tier for opensource projects. I did some experimentation with GitHub Actions and the configuration file is close enough to Travis that I made the move away from Travis.
travis-ci.org has sadly backed down from the "Testing your open source projects will always be free!" they are still advertising on their page and forcing everyone still wanting to use the service to migrate to travis-ci.com which doesn't have a similar free tier for opensource projects. I did some experimentation with GitHub Actions and the configuration file is close enough to Travis that I made the move away from Travis.