If we attempt to push a mirror to a host we've never connected to
before, it won't be in the SSH known hosts and the mirror will fail.
This makes a new host_key parameter required and the role takes care
of setting it up in the known_hosts for the duration of the job.
Change-Id: I4bd40a289003fe3e88c9af4029576236c064fc3d
Depends-On: https://review.openstack.org/#/c/649183/
This role is meant to replicate a successfully tested git repository
to a remote git server over SSH during the POST pipeline.
Change-Id: I562802ede7358c809c915f09f229884d81cc5b31
Depends-On: https://review.openstack.org/643435