Move away from travis-ci

[san650]

travis is not working right now, we should move to something else. Github actions?

@ro0gr thoughts?

[ro0gr]

I'm not sure what happened to Travis, and why it doesn't really work. I think I'd give a try to GH Actions, cause if it'd start to work smoothly I can see no reason to not migrate.

Honestly, I don't have much of experience with neither Travis nor GH Actions configuration, but it seems like the community is actively moving towards the GH actions. For example, here is the latest ember's blueprint output for the default CI provider in ember-cli@4 - https://github.com/ember-cli/ember-addon-output/blob/master/.github/workflows/ci.yml

[san650]

I think cloning that workflow is all that we need. It would be great if you could give it a try, if you don't have time, let me know and I can migrate it.

Thanks @ro0gr

[ro0gr]

just for the reference, it's solved in the #552