Push RC packages to an 'unstable' repo on packages.gitlab.com
With the recent changes to cookbook-omnibus-gitlab, it is now hard to install any omnibus package on gitlab.com that is not on packages.gitlab.com.
I think we need a place where we can push unstable packages like release candidates. E.g. packages.gitlab.com/gitlab/unstable.
If we make that then we could adapt the Makefile to push RC's there.