Create ACL groups for oslo.rootwrap

The primary maintainer of oslo.rootwrap (ttx) is not in the oslo-core
group. Rather than remembering to treat his +1 as a +2, we should have
a separate group for managing oslo.rootwrap, as we do with some of the
other oslo libraries.

Change-Id: Iace9566d182444b11cc4936081ad9bf181865e4c
Merge "Create ACL groups for oslo.rootwrap"