Mention Java 17 in README.md

README.md

-# An example Java 11 project using Maven and JUnit 5.x
+# An example Java 17 project using Maven and JUnit 5.x
 
-1. Get adoptopenjdk-11: https://adoptopenjdk.net/
+1. Get adoptopenjdk-17: https://adoptopenjdk.net/
 2. Get maven 3.6.x: https://maven.apache.org/
 3. Add above to your path if neccessary.
 4. `git clone git@github.com:example/test.git`