Refactor docker push task
Part of #2071 (closed)
This MR introduces a couple of changes to our build/release process, all of them related to Docker image builds:
- GitLab Docker image gets pushed to dev.gitlab.org registry during both branch and tag builds
- Nightly Docker image still gets pushed to public. This is OK since our master should not contain any security related changes.
- On tag build, a new manual step is created
- This manual step is used by RM to release the image to the public
- The image is already built and available on dev.gitlab.org
- Once the manual job is started, image will be pulled from the staging registry and pushed to dockerhub
Edited by Marin Jankovski