setup new createGame-Method

fh.fd.ci.server/src/main/java/de/fd/fh/server/game/GameService.java

@@ -1,5 +1,6 @@
 package de.fd.fh.server.game;
 
+import de.fd.fh.server.user.UserId;
 import lombok.RequiredArgsConstructor;
 
 @RequiredArgsConstructor
@@ -11,4 +12,9 @@ public class GameService
     {
         return (GameId) repository.save(game).getId();
     }
+
+    public GameId createGame(final UserId blackUser, final UserId whiteUser)
+    {
+        return null;
+    }
 }