Race condition in counting number of attempts #567 (#697)

Add version to Hibernate mapping so we get optimistic locking this solves
number of parallel calls trying to update/guess and mess with the lesson
counter

webgoat-container/src/main/resources/db/container/V2__version.sql

@@ -0,0 +1 @@
+ALTER TABLE CONTAINER.LESSON_TRACKER ADD VERSION INTEGER;