RI-445 Change default maas version
RI-445 Change default maas version

This changes the maas_release variable from 'undefined' to 'master'.

jacobwagner/rpc-openstack,BjoernT/rpc-openstack,BjoernT/rpc-openstack,rcbops/rpc-openstack,jacobwagner/rpc-openstack,rcbops/rpc-openstack