add mocking functions for tests

src/repositories/ApiBasedRepository.ts

@@ -1,16 +1,14 @@
 import { GetterRepository } from "./GetterRepository";
 import { IEta } from "../entities/entities";
 
+// TODO: implement
+
 export class ApiBasedRepository implements GetterRepository {
   public async getEtaForShuttleAndStopId(shuttleId: string, stopId: string): Promise<IEta | null> {
-    // TODO: implement
-
     return null;
   }
 
   public async getEtasForShuttleId(shuttleId: string): Promise<[]> {
-    // TODO: implement
-
     return [];
   }