List devices in settings file and print versions

def list_devices(names=None, continue_from=None, **kwargs):
    """List devices in settings file and print versions"""

    if not names:
        names = [device for device, _type in settings.GOLDEN_DEVICES if _type == 'OpenThread']

    if continue_from:
        continue_from = names.index(continue_from)
    else:
        continue_from = 0

    for port in names[continue_from:]:
        try:
            with OpenThreadController(port) as otc:
                print('%s: %s' % (port, otc.version))
        except:
            logger.exception('failed to get version of %s' % port)