Xiaomi WiFi driver

Hubitat Driver for controlling Xiaomi WiFi devices locally, with no hub or cloud connection required.

Tested on chuangmi.plug.m1 only.

Note: Unfortunately the plug eventually stops responding to commands until you physically cycle the power to it. Others are reporting this issue too, so it appears to be a fault with the plug itself, not this driver: https://xiaomi.eu/community/threads/mi-plug-mini-socket-wifi-communication-problems.47985/

1. Add plug_m1.groovy to your Hubitat as a new Driver (under Drivers Code)
2. Add a new device for your WiFi Socket to your Hubitat, set device Type to your User driver of 'Xiaomi WiFi Socket'
3. Assign your plug a static IP, and enter the IP into the device's IP Address setting in Hubitat.
4. (Optional) If your device is linked to the Mi Cloud, it may be hiding its device token from all other requests, including this driver - if so, manually enter the token into the Device Token setting in Hubitat. Try the options here to obtain your token if you don't already know it - otherwise you may need to reset the device: https://github.com/jghaanstra/com.xiaomi-miio/blob/master/docs/obtain_token.md
5. Pressing Refresh on the device in Hubitat should now load the current switch state (on/off) and the temperature reading. Enjoy :)

References:
Mi Home Binary Protocol: https://github.com/OpenMiHome/mihome-binary-protocol
Working protocol example: https://github.com/aholstenson/miio