Fix for OPENSTACK-1065
Fix for OPENSTACK-1065

ipallocations are not used by Neutron to determine a free IP.
Availabilityranges are used instead.

Change-Id: I0ae864a89afe0e08120963f0e4a38cb5eae1f3b5
Closes-Bug: OPENSTACK-1065

naveensan1/nuage-openstack-neutron,nuagenetworks/nuage-openstack-neutron,naveensan1/nuage-openstack-neutron,nuagenetworks/nuage-openstack-neutron