LoRa Clock Synchronization and FUOTA

[sslupsky]

Version 1.3.1 (Dec 2019) of the ST firmware has the Semtech 4.4.2 stack that supports LoRa Clock Synchronization.

I think the current version used in the master branch here is still based on 1.1.2? Issue #10 indicated some work to bring it up to 1.2.0 and I noticed a 1.2.1 branch. Does those branches work?

If we can bring the firmware to 1.3.1, we would be in a position to add support for Clock Synchronization and FUOTA (Firmware Updates Over The Air).