bump to 0.5.5

CHANGELOG.md

+## 0.5.5
+* 修复ios分享小程序标题不正确的问题。
+
 ## 0.5.4
 * 增加一次性订阅消息功能。
 

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: 0.5.4
+version: 0.5.5
 author: JarvanMo <jarvan.mo@gmail.com>
 homepage: https://github.com/JarvanMo/fluwx