added Map (string, string) constructor: takes the location and connections files as arguments
changed setLocations and setConnections as private methods
updated main
Added method to clear cities properties
changed findPath to take type of heuristic as another argument and call the respective heuristic method
separated findPath method from the A* algorithms
added a new method declaration for an A* algorithm that uses the number of hops
updated main
Made changes that had to do with distance into type double