Add RGBtoHSV function.
Add custom LightState class.

The one in node-hue-api overwrites its own methods. Total clowntown. lightState.on() => sets lightState.on to a boolean.
Understand brightness and multiple commands through 'and'

Examples:
Set the lights in the living room to purple and set the brightness to high.
Turn the lights in the dining and living room on and set the brightness to low
Set the brightness of the lights in the living room to low