Test validates a logged in user
TripService returns empty trips list if user is logged in and a stranger
TripService returns populated trips list if user is logged and is a friend
Fixed merge conflicts
Created UserBuilder
User informs when users are friends
Refactored TripService
Refactored - loggedInUser passed in as parametre getTripsByUser
tripsBy(user) added to TripDAO
final refactoring on trip service