bump to 2.1.0

CHANGELOG.md

+## 2.1.0
+* Specifying supported platforms
+
 ## 2.0.9
 * Android SDK 升级到6.6.4
 * iOS SDK升级到1.8.7.1

pubspec.yaml

 name: fluwx
 description: The capability of implementing WeChat SDKs in Flutter. With Fluwx, developers can use WeChatSDK easily, such as sharing, payment, lanuch mini program and etc.
-version: 2.0.9
+version: 2.1.0
 homepage: https://github.com/JarvanMo/fluwx
 
 environment: