added rest solution for exercise 13

added the representation for the shell element in the map which will be displayed when you shoot,

Projekte/battleship/model/src/main/java/pp/battleship/game/client/AnimatonState.java

@@ -22,7 +22,7 @@ public AnimatonState(ClientGameLogic logic, boolean myTurn, IntPoint position) {
         logic.playMusic(Music.BATTLE_THEME);
         this.myTurn = myTurn;
         if(myTurn) {
-            logic.send(new AnimationEndMessage(position));
+            logic.getOpponentMap().add(new Shell(position));
         }else {
             logic.getOwnMap().add(new Shell(position));
         }