bump to 1.0.4

CHANGELOG.md

+## 1.0.4
+* 解决Android上打开小程序返回白屏问题（非官方解决方案）
+
 ## 1.0.3
 * 修复一些小问题
 

pubspec.yaml

 name: fluwx
 description: A implement of WeChatSDK on Flutter.Fluwx makes possible using WeChatSDK in Flutter.Enjoy sharing or payment in Flutter.
-version: 1.0.3
+version: 1.0.4
 author: JarvanMo <jarvan.mo@gmail.com>
 homepage: https://github.com/JarvanMo/fluwx