Add a job for functional tests in zaqarclient

We'd like to test every patch submitted for zaqarclient against a live
running zaqar server. This patch adds a new zaqarclient job that
installs zaqar and runs the client functional tests.

This job has, temporarily, been made non-voting until we're sure it
works as expected. This is a prevention to avoid blocking the client
patches on a broken job. Once it works as expected, I'll add the job to
the gate pipeline and make it voting.

Change-Id: Ia5b47bfc02b2c53ccbc2a73729961a9d5fdd9b6d
Merge "Add a job for functional tests in zaqarclient"