Implemented marker visualisation from XML in ResizableRaceCanvas

- Replaced and deprecated Constants
- Added getMarkers to RaceDataSource interface
- Added boundary testing for source data

#story[782]

visualiser/src/main/java/seng302/RaceXMLReader.java

@@ -14,6 +14,7 @@ import java.util.List;
 
 /**
  * Created by fwy13 on 26/03/2017.
+ * @deprecated use {@link seng302.Mock.StreamedCourseXMLReader}
  */
 public class RaceXMLReader extends XMLReader implements RaceDataSource {
     private List<BoatInRace> boats = new ArrayList<>();
@@ -263,6 +264,11 @@ public class RaceXMLReader extends XMLReader implements RaceDataSource {
         return new GPSCoordinate(startLat, startLong);
     }
 
+    @Override
+    public List<Marker> getMarkers() {
+        return null;
+    }
+
     public List<BoatInRace> getBoats() {
         return boats;
     }