travis-ci.org is no longer building

[fastjames]

When visiting travis-ci.org to view the current CI status for this project, the following message is displayed near the top of the page:

Since June 15th, 2021, the building on travis-ci.org is ceased. Please use travis-ci.com from now on.

Travis CI has a page of documentation about the migration here:
https://docs.travis-ci.com/user/migrate/open-source-repository-migration/#migrating-a-repository