Add support for the external network reference by it's name apart from
ID.
Include external network id in a log message of
the openstack/step_allocate_ip.
Remove usage of the deprecated OpenStack Compute service floating IP
management and add methods to work with the OpenStack Networking
service floating IPs API.
Remove usage of the deprecated OpenStack Compute service floating IP
pools and add methods to work with the OpenStack Networking service
external networks API.
Move reusable logic of working with the OpenStack Networking service API
to a separate methods in the networking.go file.
Pass error messages from the API services to the ui messages in the
allocate IP step.
Andrei Ozerov