Version 1.6.0 is currently only available on the "unstable" update channel. We need to move it to the "stable" channel soon since it appears to be working very well.
In order to switch to the "unstable" channel, log into your BrewBit.com account dashboard, select your device, go to "Device Settings" and select the "unstable" channel and then click "Update Device". Then when you check for updates on your Model-T, it will find one.