Merge branch 'ab/ci-updates'

Drop support for TravisCI and update test workflows at GitHub. * ab/ci-updates: CI: don't run "make test" twice in one job CI: use "$runs_on_pool", not "$jobname" to select packages & config CI: rename the "Linux32" job to lower-case "linux32" CI: use shorter names that fit in UX tooltips CI: remove Travis CI support