update UnitTest Ship

src/test_/java/ShipTest.java

@@ -11,5 +11,9 @@ class ShipTest {
         Ship ship = new Ship(3, "TestShip");
         assertFalse(ship.isKilled());
         assertEquals(0, ship.numOfHits);
+
+        ship.counter();
+        assertFalse(ship.isKilled());
+        assertEquals(1, ship.numOfHits);
     }
 }