Enhancements:
- Whitelist MLI lights, incl. gamut (see #439);
- Add gamut for GLEDOPTO controllers (see dresden-elektronik/deconz-rest-plugin#1204 and dresden-elektronik/deconz-rest-plugin#1205).
- Sanity check for supported colour gamut reported by Hue bridge;
- Sanity check for supported colour temperature range reported by Hue bridge or deCONZ gateway;
- Support IKEA Trådfri on/off switch (see #440);
- Thermostat: round target temperature to multiples of 0.5°C (see #426).
Bump dependencies:
- NodeJS v10.15.1 LTS;
- deCONZ v2.05.58;
- homebridge-hue-utils v2.0.9;
- homebridge-lib v4.0.5.