Update to version 1.0.0

R=floitsch@google.com

Review-Url: https://codereview.chromium.org//1654813002 .
diff --git a/CHANGELOG.md b/CHANGELOG.md
index cadcf76..f69a8aa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,22 +1,26 @@
-###0.2.3
+## 1.0.0
+
+* Change to using `package:test` for testing.
+
+## 0.2.3
 
 * Fixed strong mode analysis errors.
 * Migrated tests to package:test.
 
-###0.2.2
+## 0.2.2
 
 * Made `Isolate.kill` parameter `priority` a named parameter.
 
-###0.2.1
+## 0.2.1
 
 * Fixed spelling in a number of doc comments and the README.
 
-###0.2.0
+## 0.2.0
 
 * Renamed library `isolaterunner.dart` to `isolate_runner.dart`.
 * Renamed library `loadbalancer.dart' to `load_balancer.dart`.
 
-###0.1.0
+## 0.1.0
 
 * Initial version
 * Adds IsolateRunner as a helper around Isolate.
diff --git a/pubspec.yaml b/pubspec.yaml
index f68a76e..ae9da40 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: isolate
-version: 0.2.3
+version: 1.0.0
 author: Dart Team <misc@dartlang.org>
 description: Utility functions and classes related to the 'dart:isolate' library.
 homepage: https://github.com/dart-lang/isolate