Merge pull request #323 from Workiva/batch/client_platform/up_dart_sdk_minimum_to_2.11

Raise the Dart SDK minimum to at least 2.11.0

Author: rmconsole4-wk

pubspec.yaml

@@ -3,7 +3,7 @@ version: 6.1.2
 description: Bindings of the ReactJS library for building interactive interfaces.
 homepage: https://github.com/cleandart/react-dart
 environment:
-  sdk: '>=2.7.0 <3.0.0'
+  sdk: ">=2.11.0 <3.0.0"
 dependencies:
   js: ^0.6.0
   meta: ">=1.1.6 <1.7.0" # Workaround to avoid https://github.com/dart-lang/sdk/issues/46142