lbaas v2 member's subnet_id should be optional

[Brandon Logan]

neutron lbaas-member-create --address 10.0.0.1 --protocol-port 80 pool1
usage: neutron lbaas-member-create [-h]
                                   [-f {html,json,shell,table,value,yaml}]
                                   [-c COLUMN] [--max-width <integer>]
                                   [--prefix PREFIX]
                                   [--request-format {json,xml}]
                                   [--tenant-id TENANT_ID]
                                   [--admin-state-down] [--weight WEIGHT]
                                   --subnet SUBNET --address ADDRESS
                                   --protocol-port PROTOCOL_PORT
                                   POOL
neutron lbaas-member-create: error: argument --subnet is required

subnet should not be required but it is. The API shouldn't make it required either.

neutron-lbaas API bug:

https://bugs.launchpad.net/neutron/+bug/1426248

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/160749

[OpenStack Infra (hudson-openstack)]

Change abandoned by Numan Siddique (<email address hidden>) on branch: master
Review: https://review.openstack.org/160749

[OpenStack Infra (hudson-openstack)]

Change abandoned by Armando Migliaccio (<email address hidden>) on branch: master
Review: https://review.openstack.org/160749
Reason: This review is > 4 weeks without comment, and failed Jenkins the last time it was checked. We are abandoning this for now. Feel free to reactivate the review by pressing the restore button and leaving a 'recheck' comment to get fresh test results.

[Launchpad Janitor (janitor)]

[Expired for python-neutronclient because there has been no activity for 60 days.]