Now we can associate a qos policy to the floating IP, and
dissociate it. The commands are:
$ openstack floating ip create --qos-policy ...
$ openstack floating ip set --qos-policy ...
$ openstack floating ip set --no-qos-policy ...
$ openstack floating ip unset --qos-policy
These commands are based on the neutron change:
I4efe9e49d268dffeb3df4de4ea1780152218633b
Partially-Implements blueprint: floating-ip-rate-limit
Change-Id: I932b32f78cc5a2b53926feaec1a0b392cf7e8b57