Added Lobby and Session classes.

src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/Lobby.java

@@ -0,0 +1,5 @@
+package ch.unibas.dmi.dbis.cs108.sebaschi;
+
+public class Lobby {
+
+}

src/main/java/ch/unibas/dmi/dbis/cs108/sebaschi/Session.java

@@ -0,0 +1,9 @@
+package ch.unibas.dmi.dbis.cs108.sebaschi;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Session {
+  List<Lobby> Lobbies = new ArrayList<>();
+
+}