Draft: gitlab-ci: build docker image as part of CI run
This implements build of docker image as part of every CI run. The build should be most of the time fast as we always pull the latest version and thus reuse that if there is no update required.
Self sign-up has been disabled due to increased spam activity. If you want to get access, please send an email to a project owner (preferred) or at gitlab(at)nic(dot)cz. We apologize for the inconvenience.
This implements build of docker image as part of every CI run. The build should be most of the time fast as we always pull the latest version and thus reuse that if there is no update required.