Merge pull request #303 from rezanachmad/patch-1

Add OAuth.io to README

Author: lord

README.md

@@ -91,6 +91,7 @@ Examples of Slate in the Wild
 * [viagogo API Documentation](http://developer.viagogo.net/)
 * [Fidor Bank API Documentation](http://docs.fidor.de/)
 * [Market Prophit API Documentation](http://developer.marketprophit.com/)
+* [OAuth.io API Documentation](http://docs.oauth.io/)
 
 (Feel free to add your site to this list in a pull request!)