Add key -n for sudo utility

If user didn't configure sudo to work without password,
it'll prompt for password during the test if debug is
enabled in tempest confgiuration.
If a password is required for the command to run,
sudo with option -n will display  an error messages and exit.

Change-Id: If7cdb331b3305c39a8f58746129ec2f125e651be
1 file changed