Add rhel 7.6 image for beaker provisioning
Add rhel 7.6 image for beaker provisioning

https://beaker.engineering.redhat.com/distrotrees/96222#lab-controllers

This image was built at 2018-10-10 20:09:12 +02:00 .

Change-Id: I599533f6db2f5f027bb5197f2e99a309d9958ee3

redhat-openstack/infrared,redhat-openstack/infrared,redhat-openstack/infrared