Updated openstack/openstack
Project: openstack/sahara  5671c016d99eb6284ea8a64a1f6319b6c7531ffe

Migrate to oslo.context

The oslo.context lib version 0.1.0 has been just release and we
could migrate to it now.

Change-Id: Id2e23b0f1e42b1addf97f0b7fe08fb00fe5d17dd