Add openstack/oslo.rootwrap project

Rootwrap is being separated from the oslo-incubator. The filter-branched
proposed repository lives at https://github.com/ttx/oslo.rootwrap for
your reviewing pleasure. Initial version does not include docs (hence
the omission of the -docs jobs) and will reuse oslo-core review groups.

See https://blueprints.launchpad.net/oslo/+spec/standalone-rootwrap

Change-Id: Ieb3439d824f3aff1cbab48753b0630de30daf198
Merge "Add openstack/oslo.rootwrap project"