Added donor donation amount to the donor response

ref #66

src/models/responses/ResponseDonor.ts

@@ -1,5 +1,5 @@
 import {
-    IsBoolean
+    IsBoolean, IsInt
 } from "class-validator";
 import { Donor } from '../entities/Donor';
 import { ResponseParticipant } from './ResponseParticipant';
@@ -15,6 +15,12 @@ export class ResponseDonor extends ResponseParticipant {
     @IsBoolean()
     receiptNeeded: boolean;
 
+    /**
+    * Returns the total donations of a donor based on his linked donations.
+    */
+    @IsInt()
+    donationAmount: number;
+
     /**
      * Creates a ResponseRunner object from a runner.
      * @param runner The user the response shall be build for.
@@ -22,5 +28,6 @@ export class ResponseDonor extends ResponseParticipant {
     public constructor(donor: Donor) {
         super(donor);
         this.receiptNeeded = donor.receiptNeeded;
+        this.donationAmount = donor.donationAmount;
     }
 }