v1.2.0

• Improvements
  • Added id: pid option. In active mode, this causes the receive
    notification messages to contain the pid of the Nerves.UART GenServer that
    sends them. Thanks to Tallak Tveide for this improvement.
  • Added find_pids/0 diagnostic utility for finding lost Nerves.UART pids.
    This is handy when you need to close a serial port and don't know the pid.
  • Added configuration/1 to get the current configuration of a UART.