Needs updated to work with MagTag

This library needs to get some updates in order to work with the new Mag Tag device since it's display works a bit differently than existing ones. 

Some discussion on Discord here: https://discordapp.com/channels/327254708534116352/327298996332658690/776127623738687488

My device should be arriving in a few days, I'll make a PR with these changes once that is in hand for testing. 