Add independent DEB/RPM repositories for each new major release
As proposed in https://gitlab.com/gitlab-org/gitlab-ci-multi-runner/issues/2305#note_26617360 we should think if we should serve each major branch releases from a different repositories, so for example:
- for 9.x.y packages would be available from https://packages.gitlab.com/runner/gitlab-runner-9-x,
- after releasing 10.0, all 10.x.y packages would be available from https://packages.gitlab.com/runner/gitlab-runner-10-x,
and so on.
This would prevent users that are not pinning packages from auto-upgrading to a new versions that may be not backward compatible with used version of GitLab (which may be not upgraded automatically).
The convention is not new. The comment referenced above nodejs is mentioned. But after reading this I now remember that I saw several projects, that are hosting their own packages servers with independent repositories for different versions.