"Timed out after 10.000000s waiting for ..." when connecting to muse via example_plot.py

[bncuthbert]

On branch develop, commit b75051858452a1887d4d146d9c75657fab9a40c5. MacOS High Sierra 10.13.6. Python 3.6.5

>>> python example_plot.py
WARNING: No module named 'pexpect'
Traceback (most recent call last):
  File "example_plot.py", line 14, in <module>
    streamer = ble2lsl.Streamer(device)
  File "/Users/benc/dev/merlin/WizardHat/ble2lsl/ble2lsl.py", line 219, in __init__
    self.connect()
  File "/Users/benc/dev/merlin/WizardHat/ble2lsl/ble2lsl.py", line 310, in connect
    self._ble_device.subscribe(uuid, callback=process_packet)
  File "/Users/benc/dev/merlin/py3.6/lib/python3.6/site-packages/pygatt/device.py", line 144, in subscribe
    self._notification_handles(uuid)
  File "/Users/benc/dev/merlin/py3.6/lib/python3.6/site-packages/pygatt/device.py", line 120, in _notification_handles
    value_handle = self.get_handle(uuid)
  File "/Users/benc/dev/merlin/py3.6/lib/python3.6/site-packages/pygatt/device.py", line 202, in get_handle
    self._characteristics = self.discover_characteristics()
  File "/Users/benc/dev/merlin/py3.6/lib/python3.6/site-packages/pygatt/backends/bgapi/device.py", line 21, in wrapper
    return func(self, *args, **kwargs)
  File "/Users/benc/dev/merlin/py3.6/lib/python3.6/site-packages/pygatt/backends/bgapi/device.py", line 141, in discover_characteristics
    self._handle)
  File "/Users/benc/dev/merlin/py3.6/lib/python3.6/site-packages/pygatt/backends/bgapi/bgapi.py", line 428, in discover_characteristics
    timeout=10)
  File "/Users/benc/dev/merlin/py3.6/lib/python3.6/site-packages/pygatt/backends/bgapi/bgapi.py", line 532, in expect
    return self.expect_any([expected], *args, **kargs)
  File "/Users/benc/dev/merlin/py3.6/lib/python3.6/site-packages/pygatt/backends/bgapi/bgapi.py", line 568, in expect_any
    raise exc
pygatt.backends.bgapi.exceptions.ExpectedResponseTimeout: Timed out after 10.000000s waiting for [<EventPacketType.attclient_procedure_completed: 17>]