Transition some travis checks to GithubActions

[staabm]

parallize more jobs to speedup the overall CI build time.

In GithubActions we can get up to 8 parallel workers, while on travis its limited to 4.
current overall build time is ~17-18 min. distribution of the jobs should make it faster.

[staabm]

@TomasVotruba could you activate GithubActions for this repo?

[TomasVotruba]

I added some file to master. Is that the activation?

[staabm]

thx!

hmm I guess I cannot create new githubaction workflows because I am not a repo owner.

just reverted the changes to travis.yml so we could merge this as is and would iterate on the result in a new PR. I guess I can modify a then existing workflow, but creating a new one, as I did here is not allowed as a external collaborateur.

if it works as expected we can drop the travis.yml jobs afterwards.

[staabm]

(Alternatively you could take my changes and create a PR yourself)

[TomasVotruba]

I've invited you as a collaborator, so you can can create a branch in here instead of work.

Could you re-check?

[staabm]

Thx for the invitation. It seems I dont have permissions to create new branches in this repo

[TomasVotruba]

Let's merge it and see