Work around a CFE inference bug (#5)

Annotate the type of All.variables and None.variables to work around
dart-lang/sdk#32412.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index e4a9f72..367abee 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 1.0.3
+
+* Work around an inference bug in the new common front-end.
+
 ## 1.0.2
 
 * Declare compatibility with `string_scanner` 1.0.0.
diff --git a/lib/src/all.dart b/lib/src/all.dart
index e15230b..f4b2c1f 100644
--- a/lib/src/all.dart
+++ b/lib/src/all.dart
@@ -6,7 +6,9 @@
 
 /// A selector that matches all inputs.
 class All implements BooleanSelector {
-  final variables = const [];
+  // TODO(nweiz): Stop explicitly providing a type argument when sdk#32412 is
+  // fixed.
+  final variables = const <String>[];
 
   const All();
 
diff --git a/lib/src/none.dart b/lib/src/none.dart
index 35970b5..637f185 100644
--- a/lib/src/none.dart
+++ b/lib/src/none.dart
@@ -6,7 +6,9 @@
 
 /// A selector that matches no inputs.
 class None implements BooleanSelector {
-  final variables = const [];
+  // TODO(nweiz): Stop explicitly providing a type argument when sdk#32412 is
+  // fixed.
+  final variables = const <String>[];
 
   const None();
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 4425998..27961af 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: boolean_selector
-version: 1.0.3-dev
+version: 1.0.3
 description: A flexible syntax for boolean expressions.
 author: Dart Team <misc@dartlang.org>
 homepage: https://github.com/dart-lang/boolean_selector