Update persistence unit name

Author: timKraeuter

src/main/java/no/hvl/dat250/jpa/tutorial/creditcards/driver/CreditCardsMain.java

@@ -6,7 +6,7 @@
 
 public class CreditCardsMain {
 
- static final String PERSISTENCE_UNIT_NAME = "jpa-example";
+ static final String PERSISTENCE_UNIT_NAME = "jpa-tutorial";
 
  public static void main(String[] args) {
  try (EntityManagerFactory factory = Persistence.createEntityManagerFactory(