Update glance_store to 0.20.0
Update glance_store to 0.20.0

Change-Id: I9cf7d1d331808548cec1f56bb529e7c22612cee5
Depends-on: Id093c5126e4c8791549d8d65a3f1a79da0dd4c9e

openstack/rpm-packaging,openstack/rpm-packaging