Sort revisions by revision number.

Timestamps might not be unique, but the revision number "should form a strictly-increasing sequence of numbers".

See https://docs.jboss.org/hibernate/orm/5.2/javadocs/org/hibernate/envers/RevisionNumber.html
Closes #3579

Author: schauder

Diff for: spring-data-envers/src/main/java/org/springframework/data/envers/repository/support/EnversRevisionRepositoryImpl.java

@@ -96,7 +96,7 @@ public EnversRevisionRepositoryImpl(JpaEntityInformation<T, ?> entityInformation
 	public Optional<Revision<N, T>> findLastChangeRevision(ID id) {
 
 		List<Object[]> singleResult = createBaseQuery(id) //
-				.addOrder(AuditEntity.revisionProperty("timestamp").desc()) //
+				.addOrder(AuditEntity.revisionNumber().desc()) //
 				.setMaxResults(1) //
 				.getResultList();