Try it now - version 1.1.2 with support for string co-ordinates.
Forecast.io is changing their name to darksky.net.
New API address is api.darksky.net (instead of api.forecast.io)
http://status.darksky.net/2016/09/20/forecast-api-is-now-dark-sky-api.html
And if you update your #require line to #require "DarkSky.class.nut:1.0.1", you’re good to go!
Thanks! I mentioned the library to DarkSky and they added a link on their site: