maint/CICD ~ (TravisCI) *remove* TravisCI (TravisCI no longer support…

…s FOSS)

- TravisCI has been degraded by a corporate take over and no longer supports FOSS projects
- ref: <https://travis-ci.community/t/intending-to-use-travis-for-a-foss-project-forget-it/11406> @@ <https://archive.is/WAPWF>
- ref: <https://news.ycombinator.com/item?id=25338983> @@ <https://archive.is/WrqaC>