Correctly use AbstractDTO in restful booker tests

src/test/java/com/frameworkium/integration/heroku/restfulbooker/api/dto/booking/Booking.java

@@ -4,7 +4,7 @@
 
 import java.util.concurrent.ThreadLocalRandom;
 
-public class Booking extends AbstractDTO {
+public class Booking extends AbstractDTO<Booking> {
     public String firstname;
     public String lastname;
     public long totalprice;

src/test/java/com/frameworkium/integration/heroku/restfulbooker/api/dto/booking/BookingDates.java

@@ -5,7 +5,7 @@
 import java.time.LocalDate;
 import java.time.format.DateTimeFormatter;
 
-public class BookingDates extends AbstractDTO {
+public class BookingDates extends AbstractDTO<BookingDates> {
 
     public static final DateTimeFormatter FORMAT =
             DateTimeFormatter.ISO_LOCAL_DATE;

src/test/java/com/frameworkium/integration/heroku/restfulbooker/api/dto/booking/BookingID.java

@@ -2,7 +2,7 @@
 
 import com.frameworkium.core.api.dto.AbstractDTO;
 
-public class BookingID extends AbstractDTO {
+public class BookingID extends AbstractDTO<BookingID> {
 
     public int bookingid;
 

src/test/java/com/frameworkium/integration/heroku/restfulbooker/api/dto/booking/BookingResponse.java

@@ -2,6 +2,6 @@
 
 import com.frameworkium.core.api.dto.AbstractDTO;
 
-public class BookingResponse extends AbstractDTO {
+public class BookingResponse extends AbstractDTO<BookingResponse> {
     public Booking booking;
 }

src/test/java/com/frameworkium/integration/heroku/restfulbooker/api/dto/booking/CreateBookingResponse.java

@@ -1,5 +1,8 @@
 package com.frameworkium.integration.heroku.restfulbooker.api.dto.booking;
 
-public class CreateBookingResponse extends BookingResponse {
+import com.frameworkium.core.api.dto.AbstractDTO;
+
+public class CreateBookingResponse extends AbstractDTO<CreateBookingResponse> {
+    public Booking booking;
     public int bookingid;
 }