added implementation and test case for TrackeRace.getCenterOfCourse

java/com.sap.sailing.server/src/com/sap/sailing/server/masterdata/DummyTrackedRace.java

@@ -605,4 +605,10 @@ public class DummyTrackedRace extends TrackedRaceWithWindEssentials {
         
     }
 
+    @Override
+    public Position getCenterOfCourse(TimePoint at) {
+        // TODO Auto-generated method stub
+        return null;
+    }
+
 }