Add a tool to run before upgrading a Monasca installation
that will check for potential issues and report on readiness to upgrade.
For Monasca, this initial version effectively does nothing, but gives a
framework for future checks to be included.
This is a community-wide story for Stein [1].
Story: 2003657
Task: 26142
[1] https://governance.openstack.org/tc/goals/stein/upgrade-checkers.html
Change-Id: I799602caa4029d67f59307bf1ca0d1e8f254d415
22be5aa57f