Added real world example of Command pattern

JUnit 4 Statement class is also an example of Command pattern. Added that to list of real world examples

Author: npathai

command/README.md

@@ -43,6 +43,7 @@ Use the Command pattern when you want to
 ## Real world examples
 
 * [java.lang.Runnable](http://docs.oracle.com/javase/8/docs/api/java/lang/Runnable.html)
+* [org.junit.runners.model.Statement](https://github.com/junit-team/junit4/blob/master/src/main/java/org/junit/runners/model/Statement.java)
 * [Netflix Hystrix](https://github.com/Netflix/Hystrix/wiki)
 * [javax.swing.Action](http://docs.oracle.com/javase/8/docs/api/javax/swing/Action.html)