[cli-ref] Update python-barbicanclient to 4.0.0
[cli-ref] Update python-barbicanclient to 4.0.0

Closes-Bug: #1488934

Change-Id: I32d914b145bd69ab2589664f49ddbd148d53bf64

openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals