turn your phone into a sensor for great justice.
for low precision passes at hardware stuff when you don't own sensors.
var senses =stringify =
ready if provided.
port is omitted it will attempt to autodetect a port.
ready is omitted, once the sensor server is ready it'll
print the url to stdout.
(err, url) as arguments.
close the sensor server.
get a new Sensor object.
Sensor objects have two