Added rule and link for real device testing

Testing across a variety of real devices is a *mandatory* part of quality assurance. Open Device Labs can help to get the hands on the necessary testbed. My NPO http://lab-up.org tries to push forward this community movement of bare sanity, and runs http://OpenDeviceLab.com to provide a platform for everybody involved.

Signed-off-by: Andre Jay Meissner <ajm@adobe.com>