971fff32b1
The rabbitmq package installed on both xenial and bionic is actually the same, allowing the vars files to be consolidated. The package has also been updated to the latest stable release, 3.7.8. The repo used for distro based installs has also been changed to packagecloud.io. New packages have not been published to rabbitmq.com for a while, the latest release there was 3.6.15. Change-Id: Id49a8788593c5d64fc9c149c8912565bc3b05a3f