created test for checking unchanged Highscore

src/test/java/Gui/GameGuiTest.java

@@ -49,4 +49,13 @@ class GameGuiTest {
         gameGui.highScore();
         assertEquals(expectedHighScore, gameGui.highScore);
     }
+	
+	@Test
+    public void testHighScoreNoNewScore() {
+        int expectedHighScore = 12;
+        gameGui.highScore = 12 ;
+        gameGui.questionNr = 3;
+        gameGui.highScore();
+        assertEquals(expectedHighScore, gameGui.highScore);
+    }
 }