As travis has ceased to support open source, the travis part of the CI has stopped for all repos in the astropy org. Some packages got moved over already, their configs could be used as guidence (e.g. pytest plugins, photutils, core).

Longer description is in this astropy-dev mail: https://groups.google.com/g/astropy-dev/c/45frnTEAX-U

Their announcement: https://blog.travis-ci.com/2020-11-02-travis-ci-new-billing