add server launcher

core/src/netwerkprog/game/server/Server.java

@@ -10,12 +10,7 @@ public class Server {
     private HashMap<String, Thread> gameThreads;
     public static final int PORT = 8000;
 
-    public static void main(String[] args) {
-        Server server = new Server();
-        server.start();
-    }
-
-    private void start() {
+    public void start() {
         this.sessionController = new SessionController();
 
         this.gameThreads = new HashMap<>();

core/src/netwerkprog/game/server/ServerLauncher.java

@@ -0,0 +1,8 @@
+package netwerkprog.game.server;
+
+public class ServerLauncher {
+    public static void main(String[] args) {
+        Server server = new Server();
+        server.start();
+    }
+}