Update JDK references

README.MD

@@ -3,7 +3,7 @@
 [![Build](https://github.com/WebGoat/WebGoat/actions/workflows/build.yml/badge.svg)](https://github.com/WebGoat/WebGoat/actions/workflows/build.yml)
 [![Coverage Status](https://coveralls.io/repos/WebGoat/WebGoat/badge.svg?branch=develop&service=github)](https://coveralls.io/github/WebGoat/WebGoat?branch=master)
 [![Codacy Badge](https://api.codacy.com/project/badge/b69ee3a86e3b4afcaf993f210fccfb1d)](https://www.codacy.com/app/dm/WebGoat)
-[![java-jdk](https://img.shields.io/badge/java%20jdk-15-green.svg)](https://jdk.java.net/)
+[![java-jdk](https://img.shields.io/badge/java%20jdk-16-green.svg)](https://jdk.java.net/)
 [![OWASP Labs](https://img.shields.io/badge/owasp-lab%20project-f7b73c.svg)](https://www.owasp.org/index.php/OWASP_Project_Inventory#tab=Labs_Projects)
 [![GitHub release](https://img.shields.io/github/release/WebGoat/WebGoat.svg)](https://github.com/WebGoat/WebGoat/releases/latest)
 [![Gitter](https://badges.gitter.im/OWASPWebGoat/community.svg)](https://gitter.im/OWASPWebGoat/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge)
@@ -68,7 +68,7 @@ WebWolf will be located at: http://localhost:9090/WebWolf (change ports if neces
 
 ### Prerequisites:
 
-* Java 15
+* Java 16
 * Maven > 3.2.1
 * Your favorite IDE
 * Git, or Git support in your IDE