add GameService

src/main/java/de/hsfulda/onses/services/GameService.java

@@ -0,0 +1,14 @@
+package de.hsfulda.onses.services;
+
+import de.hsfulda.onses.models.Game;
+
+public class GameService {
+    private final Game game;
+    public GameService(Game game) {
+        this.game = game;
+    }
+    public GameService() {
+        this(new Game());
+    }
+
+}