Prepare for Dart v2
diff --git a/pubspec.yaml b/pubspec.yaml
index 3678e31..b58896a 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,11 +1,11 @@
 name: boolean_selector
-version: 1.0.2
+version: 1.0.3-dev
 description: A flexible syntax for boolean expressions.
 author: Dart Team <misc@dartlang.org>
 homepage: https://github.com/dart-lang/boolean_selector
 
 environment:
-  sdk: '>=1.8.0 <2.0.0'
+  sdk: '>=1.8.0 <2.0.0-dev.infinity'
 
 dependencies:
   collection: '^1.5.0'