* The application of the version check in unit_of_measurement was
messed up after the last refactor. Fix that again.
* An error could occur in device_state_attributes if there was a
mismatch between used value_type in the device and mysensors
version in config. Add try... except to handle that.
Bump pyvera version.
Bump pywemo version.
Add unavailable status before properly initialised for maker and insight.
d773ad1ecb