message: Assume OT_SMOOTHIE_ID is AMA if environmental variable is unset.
  This should allow graceful handling where OT_SMOOTHIE_ID is unset. I'm not clear of any situation where the current default (FT232R) would be useful and I presume it is vestigial but I may be unaware of a situation in for example old robots.
diff: @@ -528,7 +528,7 @@ class SmoothieDriver_3_0_0:
  def _connect_to_port(self, port=None):
  try:
  - smoothie_id = environ.get('OT_SMOOTHIE_ID', 'FT232R')
  + smoothie_id = environ.get('OT_SMOOTHIE_ID', 'AMA')
  self._connection = serial_communication.connect(
  device_name=smoothie_id,
  port=port,
  