Fix neutron resource cleanup issue
Fix neutron resource cleanup issue

Remove ports before router and net removal, otherwise the net-resource
destroy will fail.

Change-Id: I2f81802b4ce9e34f583e3ab60bf22c7e5d2f0629
Partial-bug: #1488757

dtroyer/grenade,dtroyer/grenade,openstack-dev/grenade,openstack-dev/grenade