API for configuring repository push mirroring via HTTP
Problem to solve
We support HTTP push mirroring via the UI but not the API only.
Support for HTTP pull mirroring was implemented in https://gitlab.com/gitlab-org/gitlab-ee/issues/1499
Multiple pull mirroring targets are supported, so we probably need a new resource, like
Links / references
Zendesk ticket: https://gitlab.zendesk.com/agent/tickets/103762 (Internal use)