Add script to document deleting private networks
Add script to document deleting private networks

In order to test clouds with no private networks, we need to delete
the ones made by devstack. This is how that works.

Change-Id: I6c9d4d62ea34372d53399aa2b8b27b762d53339b

dtroyer/python-openstacksdk,openstack-infra/shade,stackforge/python-openstacksdk,openstack/python-openstacksdk,dtroyer/python-openstacksdk,openstack/python-openstacksdk,openstack-infra/shade,stackforge/python-openstacksdk