assess_endpoint_bindings needs to support maas 2.2 cli

The assess_endpoint_bindings.py script cannot setup spaces with the maas 2.2 cli. The "subnets create" command no longer accepts the space otion

     maas finfolk-vmaas subnets create cidr=10.0.40.0/24 fabric=729 vlan=7097 space=73 gateway_ip=10.0.40.1
{"vlan": ["Select a valid choice. That choice is not one of the available choices."], "fabric": ["Select a valid choice. That choice is not one of the available choices."], "space": ["Spaces may no longer be set on subnets. Set the space on the underlying VLAN."]}

The command may want a vlan or a fabric. The script would choose vlan because it created it. The space arg is now on the vlan.