Support for Google Cloud Build's cloudbuild.yaml

[hazcod]

Google Cloud Build is a widely used CI/CD pipeline that integrates with Github, is automatically picks up a cloudbuild.yaml file.
One can define build steps:

- steps:

- name: '<IMAGE>'
....

where name will be a docker image, residing on a public and/or private registry.

[github-actions]

👋 This issue has been marked as stale because it has been open for 2 years with no activity. You can comment on the issue to hold stalebot off for a while, or do nothing. If you do nothing, this issue will be closed eventually by the stalebot. Please see CONTRIBUTING.md for more policy details.

[steebchen]

not stale!