Fix name and future-proof Gist for Robots plugin

Hey there!

I hope you don't mind...
This started as just a plugin name change, and then I ended up creating a class in the event that you decide to extend the gist API or the github API a bit in the future.

The initial change included changing the plugin name from Gist for Boots... to Gist for Robots. :)

Thanks,
Courtney