Mark IPv6 job as non-voting to unblock the gate
Mark IPv6 job as non-voting to unblock the gate

The default dhcp client in tinycore does not automatically trigger
IPv6 address acquisition.

This is a problem when the random spread of nodes and devstack
cause tinycore to get pulled in for the v6 job.

Change-Id: I635a69dfd7450a218474ccb7cecf1c9e29c0a43c

openstack/ironic,openstack/ironic