re #9422 Commented detector.py, event_listener.py, and usb_reader.py
re #9422 Commented both config files and api_client.py.
re #9421 Restructured the test folder
re #9421 Added unit tests for resend_cached_payload() and send_data(); moved api_client.py into usb_detector package
re #9421 Added unit tests for get_metadata() and send_payload_to_server()
re #9421 Added unit tests for get_connected_devices() and get_disconnected_devices()
re #9420 Created folders src and resources; renamed config.ini to client.conf