escape '%' when encoding device ID.

Hi there, device ID's can contain %. (For example if a product class were G-240G-P genie would encode this as part of the device id as G%2D240G%2DP.

This:

requests.utils.quote(device_id)

Needs to be:

requests.utils.quote(device_id, safe='%')

Great module by the way! I was in the process of writing the same when I stumbled upon yours :)