instack-undercloud is no longer in use by the TripleO project. Removing
the code to avoid confusion. Stable branches will continue to be
maintained for their life however no new features should be added.
Change-Id: I63a813c7c1ffd30ca30017133d31a497b77a9a4d
Blueprint: remove-instack-undercloud
Currently it implies that we support booting from volumes in the undercloud,
which is not the case yet. Change the option description accordingly.
Change-Id: Ie2d92f3e5e4301375290a66553e2afb3cec6da80
Closes-Bug: #1692522