Channel shapes not provided in describe

[ksunden]

# fake spectrometer, c is yaqc.Client, d is yaqc_bluesky.Device
>>> c.id()
{'name': 'wa', 'kind': 'fake-spectrometer', 'make': None, 'model': None, 'serial': None}
>>> c.get_channel_shapes()
{'counts': [551]}
>>> d.describe()
OrderedDict([('wa_counts', OrderedDict([('source', 'yaq:wa'), ('yaq_port', 38989), ('yaq_host', '127.0.0.1'), ('shape', ()), ('dtype', 'number'), ('units', None)])), ('wa_wavelengths', OrderedDict([('source', 'yaq:wa'), ('yaq_port', 38989), ('yaq_host', '127.0.0.1'), ('shape', ()), ('dtype', 'number'), ('units', 'nm')]))])

Note that describes shape is always (), not (551) as expected for this channel (and mapping)