Added gitstats repository link to README

README.md

@@ -15,3 +15,5 @@ opencpu_r_api()
 ```
 
 For more information about OpenCPU apps, see [opencpu.js](https://www.opencpu.org/apps.html)
+
+See [gitstats](https://github.com/rwebapps/gitstats/) for a simple OpenCPU app.