修正PubSpec错误

6c5b50a9 · Kevin · 4e45045a · 6c5b50a9
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -5,7 +5,7 @@ author: Kevin <liangkaikevin@gmail.com>
 homepage: https://github.com/Im-Kevin/cool_ui

 environment:
-  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+  sdk: ">=2.0.0 <3.0.0"
  flutter: ">=1.17.0 <2.0.0"

 dependencies: