Fixed nullpointer when boat passes finish line.

- Added a condition in calculateBearingToNextMethod to avoid nullpointer

racevisionGame/src/main/java/mock/model/MockBoat.java

@@ -75,7 +75,15 @@ public class MockBoat extends Boat {
 
         //Get the start and end points.
         GPSCoordinate currentPosition = this.getCurrentPosition();
-        GPSCoordinate nextMarkerPosition = this.getCurrentLeg().getEndCompoundMark().getAverageGPSCoordinate();
+        GPSCoordinate nextMarkerPosition;
+
+        // if boat is at the finish
+        if (this.getCurrentLeg().getEndCompoundMark() == null) {
+            nextMarkerPosition = currentPosition;
+        }
+        else {
+            nextMarkerPosition = this.getCurrentLeg().getEndCompoundMark().getAverageGPSCoordinate();
+        }
 
         //Calculate bearing.
         Bearing bearing = GPSCoordinate.calculateBearing(currentPosition, nextMarkerPosition);