Update README.md adding go-sotify

Adding go-spotify to Third API libraries.
Simple API Library to access Spotify WEB API.

README.md

@@ -458,6 +458,7 @@ Please take a quick gander at the [contribution guidelines](https://github.com/a
 * [shopify](https://github.com/rapito/go-shopify) - Go Library to make CRUD request to the Shopify API. 
 * [smite](https://github.com/sergiotapia/smitego) - Go package to wraps access to the Smite game API.
 * [snapchat](https://github.com/jamieomatthews/gosnap) - Go wrapper for the snapchat API
+* [spotify](https://github.com/rapito/go-spotify) - Go Library to access Spotify WEB API. 
 
 
 ## Utilities