Bump to 0.22.2 (#82)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index db46b07..2f318ea 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## HEAD
+## 0.22.2
 
 * Add `toObservableList` and `toObservableMap`, better typed versions of
   `toObservable`.
diff --git a/pubspec.yaml b/pubspec.yaml
index 14b0cc8..33cfecf 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: observable
-version: 0.22.1+5
+version: 0.22.2
 author: Dart Team <misc@dartlang.org>
 description: Support for marking objects as observable
 homepage: https://github.com/dart-lang/observable