Juno all the things.

This brings all (except horizon) up to Juno stable branch release. Horizon is being upgraded to Icehouse.

This also introduces an upgrade.yml playbook that can be used to upgrade from havana to juno. This could be renamed, or take options, but for now will be useful for upgrading from pre-juno to juno.

Tests pass in jenkins, as well as rally tests.
Document: these keys will need to existing for all existing stacks.