I began to do this with your help...

at this point of time this would be some more work. because the gitlab is only a mirror of GitHub, the repo doesn't need any maintenance, so I would vote for keeping the gitlab account a "person".

The beta-software is now mirrored to https://gitlab.com/apertus/beta-hardware. Wen somebody who's more into building the software manually could write a .gitlab-ci.yml and add it to the GitHub repository the builds would start automatically on every commit.

done

gitlab ci is indeed a good idea :). the mirroring from github is also possible in the public instance but very bugy. to work around this we can create another repository with gitlab ci, which only pulls from github and pushes to gitlab, and is triggered by a github webhook. I did exactly this setup for another project and it works very well...
(https://github.com/freifunkks/site-ffks/tree/beta) the mirror repo can be found here: https://gitlab.com/freifunkks/mirror-scripts

I think travis wouldn't be the optimal solutions for firmware builds, because we need some special tools with proprietary licenses for building the fpga bitstreams and more build time than the 50 minutes travis gives you for free. Imo http://concourse.ci would be a good solution, because it would allow us to create quite modular pipelines for the firmware.