UnhandledPromiseRejectionWarning (Window Cover)
Hello Luke,

as previously described I get this error message when pressing a window cover with the current version. My config has not changed for a while.

![37576866-d37b99b0-2b2e-11e8-8cd3-c15d7014de1d](https://user-images.githubusercontent.com/27686185/37585642-14d1b2d4-2b5a-11e8-85a5-cc8b5f2d305c.jpeg)

[config.txt](https://github.com/lprhodes/homebridge-broadlink-rm/files/1824264/config.txt)
