- Remove Precise-Icehouse Amulet test definitions if they exist.
- Add Xenial-Newton Amulet test definitions.
- Add Yakkety-Newton Amulet test definitions.
- Use the percona-cluster charm in tests instead of the mysql charm.
- Remove local keystone auth test helper, use charm helper instead.
Change-Id: I42a43f3bad1233d18859307f39444121c98b4665