Pass private key file from parent Ansible to Kubespray
Pass private key file from parent Ansible to Kubespray

The private key file is not part of the inventory in our case, but
it's a global Ansible parameter. Make sure that we carry the same
--private-key parameter from parent Ansible run into Kubespray.

Change-Id: If6e341ee52f9d4944ee1855d3339e26b9a485dd0

openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates