Travelable interface

Signed-off-by: HeshamTB <hishaminv@gmail.com>

src/Route.java

@@ -1,4 +1,4 @@
-public class Route {
+public class Route implements Travelable {
 
     private Street[] streets;
     private District hotelArea;

src/Street.java

@@ -1,6 +1,6 @@
 import java.util.ArrayList;
 
-public class Street {
+public class Street implements Travelable {
 
     private double length;
     private int numberOfLanes;

src/Travelable.java

@@ -0,0 +1,3 @@
+public interface Travelable {
+    String getFastestTimeOfTravel(Vehicle vehicle);
+}