Update ReadMe for Python 3.6 & alternative ATC firmware

[rjblake]

Many thanks for this code. I am trying it out on my setup. A couple of observations as follows:

• Code requires Python 3.6 or higher (perhaps add as a note) - spent some time debugging syntax error before realising I was running Python 3.5.3
• My cron job would not run - needed to edit the first line to point to Python3.6 in different location (maybe this helps others)
• There is an alternate firmware for these devices (here). This looks like it will offer more control and ultimately better battery life with some pending updates. Instead of fetching the temp/hum/batt info from the sensor, it is possible to listen for the BLE broadcast instead. Any chance you might support this?

[erdose]

Thanks for your feedback! I updated the ReadMe. I know this project but I can not support it yet. I'm thinking about it... 😄