Apparently firefox geckodriver renders the grafana home page in a different
order than chromedriver. So we wait for an element which gets rendered at the
very end.

Closes: #463

remove unnecessary steps from gitlab ci, checkout correct version of rocketchat chart, check certs of OO and grafana

Closes: #385

Currently, Nextcloud installation is a pain where a lot of jobs and pod
fail until NC is finally installed. Still they show up in proemetheus and
create noise, why we ignore them in this check.
Once we achieve a better NC installation we should revert this.

Closes: #379

Closes: #291