Switch to xenial: python-k8sclient
Switch to xenial: python-k8sclient

The repo is the only user of tox-with-sudo, change the node to xenial.
The repo has only a master branch, so no need for a trusty job - and the
name is already long, let's try to avoid adding the node to it.

Change-Id: Ia1da96c1a334d0ac36a0dba303cb4cdaec0207a9

Tesora/tesora-project-config,openstack-infra/project-config,Tesora/tesora-project-config,openstack-infra/project-config