Xiaomi Robot Vacuum Binding

@marcel_verpaalen I see a lot of these in my logs for my vacuum. They’re INFO level, so while I don’t know the cause, they appear to be harmless. In the short term, I’ll probably change the log level to WARN in order to suppress them. But, I thought I’d mention it here.

I’m running this version of the binding.

 11 │ Active   │  80 │ 2.2.0.201710221505     │ org.openhab.binding.miio
2017-11-30 09:09:09.183 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:09:39.256 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:09:39.259 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:09:39.261 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:10:09.343 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:10:09.345 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:10:09.347 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:10:39.530 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:10:39.532 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:10:39.535 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:11:09.615 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:11:09.617 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:11:09.619 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON:
2017-11-30 09:11:39.700 [INFO ] [nal.transport.MiIoAsyncCommunication] - Received message is invalid JSON: