Example:
terraformer import openstack --resources=compute,networking --regions=RegionOne
List of supported OpenStack services:
blockstorageopenstack_blockstorage_volume_v1openstack_blockstorage_volume_v2openstack_blockstorage_volume_v3
computeopenstack_compute_instance_v2
networkingopenstack_networking_secgroup_v2openstack_networking_secgroup_rule_v2