Mirror gear - it's needed by tripleo-ci.

This runs in the restricted openstack-mirror only environment so we
need it here to have access to it.

Change-Id: Ibe912c0dec503d8d08c0f69751d1cd14887730ff
Merge commit 'refs/changes/81/68181/1' of git://gold.eng.hq.xensource.com/git/github/openstack/requirements into tmpbranch