Added a small test for the timer function

-More needed once scaling is in effect

#test #story[16]

src/test/java/seng302/Model/RaceTest.java

@@ -98,4 +98,16 @@ public class RaceTest {
         assertTrue(unFinishedBoat.getDistanceTravelledInLeg() < 100);
 
     }
+
+    @Test
+    public void timerDelaysByHalfSecond() {
+        ConstantVelocityRace race = new ConstantVelocityRace(new BoatInRace[1], new ArrayList<>());
+        race.PRERACE_TIME = 500;
+
+        long timeStarted = System.currentTimeMillis();
+        race.countdownTimer();
+
+        assertTrue(System.currentTimeMillis() - timeStarted > 500);
+
+    }
 }