Prepare to publish (#566)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e786f21..ff0b8c9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 0.13.3-dev
+## 0.13.3
 
 * Validate that the `method` parameter of BaseRequest is a valid "token".
 
diff --git a/pubspec.yaml b/pubspec.yaml
index bd1d547..9d14110 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: http
-version: 0.13.3-dev
+version: 0.13.3
 homepage: https://github.com/dart-lang/http
 description: A composable, multi-platform, Future-based API for HTTP requests.