refactoring done in several classes

src/test/java/ch/zhaw/pm2/racetrack/CarTest.java

@@ -101,7 +101,7 @@ class CarTest {
     @Test
     void movement() {
         // add all possible directions in a List
-        List<PositionVector.Direction> directions = Arrays.asList(PositionVector.Direction.values());
+        PositionVector.Direction[] directions = PositionVector.Direction.values();
 
         //position shouldn't be changed because velocity should be 0.
         car.move();

src/test/java/ch/zhaw/pm2/racetrack/GameTest.java

@@ -20,9 +20,9 @@ class GameTest {
     private Game game;
     private Track track;
 
-    private String TRACK_FILE_PATH = ".\\tracks\\challenge.txt";
-    private int CAR_INDEX_ONE = 0;
-    private int CAR_INDEX_TWO = 1;
+    private final String TRACK_FILE_PATH = ".\\tracks\\challenge.txt";
+    private final int CAR_INDEX_ONE = 0;
+    private final int CAR_INDEX_TWO = 1;
 
     /**
      * This nested Class tests if the game gets initiatet correctly