get_light_info: Get info on lights connected to your Hue hub
Description
This will return a dataframe containing information about the lights
connected to your hue hub. It includes info on current, colour, is it on,
and is it powered/reeachable.
If the file listed here exists, it will try and use the private keys created by the function save_private_keys(). Just ignore if you want to manually give your bridge ip and username.