Port CI from existing project

Options:

• https://git.ethitter.com/open-source/dyndnsd-client/-/blob/master/.gitlab-ci.yml
• https://git.ethitter.com/debian/eth-log-alerting/-/blob/master/.gitlab-ci.yml
• https://git.ethitter.com/debian/gitlab-runner-do-monitor/-/blob/master/.gitlab-ci.yml