Changes:
- attribute: "dimmer"  to  "brightness"
- method "dim" to  "set_brightness", with "target" replaced by "brightness"
- overload turn_on()/turn_off() with an optionnal "smooth" parameter

Add:
- attribute: "white_temperature" of the White, in Kelvin, from 1000 to 10000
  https://developer.amazon.com/fr/docs/device-apis/alexa-colortemperaturecontroller.html
- method "set_white_temperature"
- in methods, add a "smooth" parameter in milliseconds, for a smooth change delay