check_beacon_presence.py + test_beacon.py -> python3

[Maikeleg]

Many thanks to Damsee on Domoticz forum I could get the current files updated to run with Phyton3 (see link https://www.domoticz.com/forum/viewtopic.php?p=234199#p234199) The following files are updated to run with python v3 (3.7.3) on Domoticz (2022.1); check_beacon_presence.py test_beacon.py check_beacon_presence.py.txt test_beacon.py.txt rssi commented because not working (yet?) with Minew E9 beacon (tip; firmware update will brick them)