message: basket.service.ts: Make coupon optional
diff: @@ -33,7 +33,7 @@ export class BasketService {
  return this.http.post(this.host + '/', params).pipe(map((response: any) => response.data), catchError((error) => { throw error }))
  }
  - checkout (id, couponData: string) {
  + checkout (id, couponData?: string) {
  return this.http.post(this.hostServer + '/rest/basket/' + id + '/checkout',{ 'couponData': couponData }).pipe(map((response: any) => response.orderConfirmation), catchError((error) => { throw error }))
  }
  