We'll be using t-h-t environment files to insert and remove no-ops in
the plan/stack. This should help make the update/upgrade Mistral
workflows more release-agnostic and thus reduce the risk of bugs in
mixed-release UC/OC enviornments.
Depends-On: I486ad0d44f105a6fa9fd24dcf7ac28d40ceecc27
Change-Id: If173d5f6e0be71f467bd062627e9f17e8b684b99