add bulb power callback
add bulb power callback

ppelleti/lifxjs,sinnottj/lifxjs,wiegraff13/lifxjs,wiegraff13/lifxjs,sinnottj/lifxjs,WigWagCo/lifxjs,magicmonkey/lifxjs,magicmonkey/lifxjs,ppelleti/lifxjs,WigWagCo/lifxjs