iluwatar#525 Add link to proxy blog

Author: iluwatar

proxy/README.md

@@ -37,6 +37,9 @@ are several common situations in which the Proxy pattern is applicable
 * Facilitate network connection
 * Count references to an object
 
+## Tutorials
+* [Controlling Access With Proxy Pattern](http://java-design-patterns.com/blog/controlling-access-with-proxy-pattern/)
+
 ## Presentations
 * [Proxy](https://github.com/iluwatar/java-design-patterns/tree/master/proxy/etc/presentation.html)