feat: remove Travis CI in favor of GitHub Actions
feat: remove Travis CI in favor of GitHub Actions

jackwilsdon/beets,sampsyo/beets,jackwilsdon/beets,ibmibmibm/beets,shamangeorge/beets,ibmibmibm/beets,shamangeorge/beets,shamangeorge/beets,jackwilsdon/beets,shamangeorge/beets,beetbox/beets,sampsyo/beets,ibmibmibm/beets,sampsyo/beets,ibmibmibm/beets,beetbox/beets,jackwilsdon/beets,beetbox/beets,sampsyo/beets,beetbox/beets