Class LoRaGpio method monitor(...) does not work as expected.

[wke67]

The current code on github is a major improvement compared to the pypi.org release version 1.4.0. since it gets rid of the RPIO.GPIO which depends on gpiod <2.0.0!!
After adding the monitor_continuous method to class LoRaGpio (issue #38) it turns out, that the seqno variable returned by request.read_edge_events(...) is always 1 and the LoRaRF.request(RX_CONTINUOUS) will hang. The reason is, that the code construct using a with statement to do the operation on the gpio line. This will always request the gpio line(s), do some operation, and release the gpio line(s) thereafter, and this will reset the event counter every time monitor() is called. Instead, the gpio line should be requested once, the Line_Request object saved, and used for all future accesses to the gpio line. The same should be done for the input and output methods of class LoRaGpio.