Note: if anyone else purchases the T-lock you need to add a file to your Zigbee2mqtt folder to support it.
Details here: http://leftfoot.com.au/blog/zigbee2mqtt-and-the-lockwood-t-lock
File:
T-lock-Zigbee2mqtt.zip (725 Bytes)
EDIT: as of v1.2.1 of zigbee2mqtt this file is no longer required.