travis is not working anymore

[GregorDeCillia]

The CI testing of STATcubeR is not working anymore due to changes on travis. Check whether it is possible to switch to https://travis-ci.com or set up a new CI with github actions: https://github.com/r-lib/actions

[GregorDeCillia]

Github actions should be fairly straightforward to set up with usethis: https://usethis.r-lib.org/reference/github_actions.html

[GregorDeCillia]

Sine STATcubeR now also supports several internal servers, it makes more sense to set up a rigorous CI/CD that runs on our internal build server and not worry about tests that run on cloud services

I might re-open this when the STATcube API becomes available for external users