bump to 1.2.0

CHANGELOG.md

+## 1.2.0
+* 分享文件
+* compileSdkVersion 29
+
 ## 1.1.4
 
 * 注册微信时会对universal link进行简单校验

pubspec.yaml

 name: fluwx
 description: A Flutter plugin allowing developers to share or pay with natvie android & iOS Wechat SDKs.
-version: 1.1.4
+version: 1.2.0
 homepage: https://github.com/JarvanMo/fluwx
 
 environment: