Allow core reviewers to forge commits on mogan
Allow core reviewers to forge commits on mogan

This is useful for fixing up the Nova and Cinder history into the
Mogan master, as a follow-up to
I2769fdb4b37ba0eaaa250ee450fe41be2ae67022 which enabled merge commit
pushing:

http://lists.openstack.org/pipermail/openstack-dev/2017-September/122837.html

Change-Id: I33a42ecee4b0f374c182e81ab8d9bcbdb1636edb

openstack-infra/project-config,openstack-infra/project-config