Added first draft of login and tour select page

lib/model/tour.dart

@@ -0,0 +1,10 @@
+import 'supplier.dart';
+import 'delivery.dart';
+
+class Tour {
+  DateTime date;
+  Supplier supplier;
+  List<Delivery> deliveries;
+
+  Tour({required this.date, required this.deliveries, required this.supplier});
+}