Add tomorrow.io provider

[RustyBower]

https://www.climacell.co/weather-api
https://www.tomorrow.io/weather-api/

[cottongin]

I guess I could make a PR but if you want to steal from me like I stole from you:
https://github.com/cottongin/sopel-climacell

There's at least a lot of code in there that can get you started on this (rather lackluster imo) API.

[dgw]

Edited the link above (and issue title) to reflect rebranding or consolidation: climacell now redirects to tomorrow.io