Mirroring to multiple repositories

Description

Mirroring repositories is already possible, only there seems to be no possibility to mirror to multiple repositories. It would be a useful addition to be able to mirror to multiple projects; for example for a setup where several different Gitlab instances are setup in a DTAP kind of environment.

Proposal

Add the ability to mirror to multiple repositories

Links / references

https://docs.gitlab.com/ee/workflow/repository_mirroring.html