Cannot connect to RFXCOM devices when running on Windows

[maxwellhadley]

On Windows, calling the flush() method of the serialport object causes the serial device to disconnect immediately (serialport issue #1409 - ReadIOCompletion error closes port after flush on Windows). This prevents all communication with the RFXCOM device. This

This issue is the underlying cause of #70 - Error - "Writing to COM port" in package node-red-contrib-rfxcom.

[maxwellhadley]

I have published rfxcom version 2.0.1 - this rolls back to serialport version 6.2.2, while including a partially-functional workaround for this issue. Unplugging the RFXCOM device and reconnecting it no longer works correctly on Windows.

[maxwellhadley]

A pull request that fixes this issue has recently been merged into serialport master. When this package is next published to npm I will update node-rfxcom to reinstate correct operation on Windows.

[maxwellhadley]

The serialport package is updated in #90 (version 2.1.0) but the flush() call is not yet reinstated - awaiting further tests.