Add notification constructors

Projekte/mdga/model/src/main/java/pp.mdga/notification/PieceInGameNotification.java

@@ -0,0 +1,11 @@
+package pp.mdga.notification;
+
+import pp.mdga.game.Color;
+
+import java.util.UUID;
+
+public class PieceInGameNotification extends Notification{
+    PieceInGameNotification(Color color, UUID id) {
+
+    }
+}