Bump oslo.rootwrap to 1.3.0.0a1 for Cinder

Cinder already requires oslo.rootwrap 1.3.0 filters so we need to
bump requirements accordingly.

This will fix a variety of rootwrap warnings that can occur when using
the new cgroups features.

Change-Id: Ia72444d054a35c3dbb34c24dbefe8f05cdebbd33
Closes-bug: #1340877
Merge "Bump oslo.rootwrap to 1.3.0.0a1 for Cinder"