Add 9.1 with liberty upgrade levels
Add 9.1 with liberty upgrade levels

All environments which are created on the 9.1 Fuel Master node have
fuel_version is equal to 9.1. This release have to be added in
UPGRADE_LEVELS with the 'liberty' compatibility to support N+1 and N+2
upgrades.

Change-Id: Ic4cd045e6d428ce5cfed65f385a689629a232332
Closes-Bug: #1625083
(cherry picked from commit c0145127c2c520a0c97beea545a1f6dd5d0a4e31)

stackforge/fuel-octane,stackforge/fuel-octane