Test the exported start package.

Previously, tests linked in to the /lib folder, exposing some functions
not available to real clients. I would like to re-factor all the test
methods associated with Message into the Socket tests so that Message
does not need to be exposed.

Author: MarkBennett

lib/start.dart

@@ -7,6 +7,8 @@ import 'src/cookie.dart';
 import 'src/message.dart';
 import 'src/socket_base.dart';
 
+export 'src/message.dart' show Message;
+
 part 'src/route.dart';
 part 'src/request.dart';
 part 'src/response.dart';

test/start_server_test.dart

@@ -6,8 +6,7 @@ import 'dart:io' hide Socket;
 import 'package:unittest/unittest.dart';
 import 'package:unittest/mock.dart';
 
-import '../lib/start.dart';
-import '../lib/src/message.dart';
+import 'package:start/start.dart';
 
 part 'message_test.dart';
 part 'vm_socket_test.dart';