Unit/E2E tests

[julianpoy]

• [x] Users
• [x] Recipes
• [x] Labels
• [x] Messages
• [ ] Shopping Lists
• [ ] Meal Plans
• [ ] Grip
• [ ] Print
• [x] UtilService
• [x] FirebaseService
• [ ] GripService
• [ ] SessionService
• [ ] MiddlewareService

[julianpoy]

The core routes have been covered. I'll be holding off on shoppingLists and mealPlans for now and focusing on some of our utils.