An environment file to enable network isolation
An environment file to enable network isolation

This commit adds an environment file which adds all
the relevant resource registry entries to enable isolated
overcloud networks.

Change-Id: I8c5e0ca300b86a38925f59c9df7831d69da9f787

trozet/tripleo-heat-templates,trozet/opnfv-tht,rdo-management/tripleo-heat-templates,openstack/tripleo-heat-templates,bcrochet/tripleo-heat-templates,bcrochet/tripleo-heat-templates,trozet/opnfv-tht,openstack/tripleo-heat-templates,trozet/opnfv-tht,bcrochet/tripleo-heat-templates,wyg3958/tripleo-heat-templates,trozet/tripleo-heat-templates,dprince/tripleo-heat-templates,wyg3958/tripleo-heat-templates,rdo-management/tripleo-heat-templates,dprince/tripleo-heat-templates