add ci/cd

[proppy]

discussed earlier with @HelgeGehring the possibility of adding CI/CD based on https://cloud.google.com/architecture/managing-infrastructure-as-code

[proppy]

prototyped https://github.com/proppy/rad-lab-deploy based on https://github.com/GoogleCloudPlatform/solutions-terraform-cloudbuild-gitops using Google Cloud Build GitHub App

[proppy]

@mgielda @kgugala, @mithro was mentioning we might want to use a similar approach to allow custom runner deployment https://github.com/antmicro/runner by just forking a repo and authorizing the Google Cloud Build GitHub App, what do you think?