Implemented the first route of the toResponse normalisationf for all classes

ref #67

src/models/entities/RunnerOrganisation.ts

@@ -1,5 +1,6 @@
 import { IsInt, IsOptional } from "class-validator";
 import { ChildEntity, ManyToOne, OneToMany } from "typeorm";
+import { ResponseRunnerOrganisation } from '../responses/ResponseRunnerOrganisation';
 import { Address } from './Address';
 import { IAddressUser } from './IAddressUser';
 import { Runner } from './Runner';
@@ -54,4 +55,11 @@ export class RunnerOrganisation extends RunnerGroup implements IAddressUser {
   public get distanceDonationAmount(): number {
     return this.allRunners.reduce((sum, current) => sum + current.distanceDonationAmount, 0);
   }
+
+  /**
+   * Turns this entity into it's response class.
+   */
+  public toResponse(): ResponseRunnerOrganisation {
+    return new ResponseRunnerOrganisation(this);
+  }
 }