For our default CI jobs, we can add a test-setup.sh script that will run
before OpenStack CI revokes sudo for the "jenkins" user.
At the moment, we cannot add the jenkins user to the docker group to
allow the jenkins user to use docker. Instead, we have to make docker
launch itself so that the jenkins group can access the socket.
Change-Id: I732d144e4635dffe8034c0d374eee591df078f52