Remove deprecated database.commitTransaction(), migrate to transaction.commit()

Remove the deprecated methods:
- DB.commitTransaction()
- DB.rollbackTransaction()
- DB.endTransaction()
- database.commitTransaction()
- database.rollbackTransaction()
- database.endTransaction()

Migrate to using try-with-resources and transaction.commit(), transaction.rollback()

ebean-test/src/test/java/org/tests/basic/TestInheritRef.java

@@ -1,5 +1,6 @@
 package org.tests.basic;
 
+import io.ebean.Transaction;
 import io.ebean.xtest.BaseTestCase;
 import io.ebean.DB;
 import org.junit.jupiter.api.Test;
@@ -17,8 +18,7 @@ public class TestInheritRef extends BaseTestCase {
   @Test
   public void testAssocOne() {
 
-    DB.beginTransaction();
-    try {
+    try (Transaction txn = DB.beginTransaction()) {
       DB.createUpdate(Vehicle.class, "delete from vehicle");
 
       Car c = new Car();
@@ -52,9 +52,6 @@ public class TestInheritRef extends BaseTestCase {
 
       assertEquals(1, found);
       assertTrue(foundTruck.getCapacity() == 20D);
-
-    } finally {
-      DB.rollbackTransaction();
     }
   }
 }