Release 0.12.0-beta.5.

R=kevmoo@google.com

Review URL: https://codereview.chromium.org//1053413003
diff --git a/CHANGELOG.md b/CHANGELOG.md
index f3e287d..c8c7e6f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,9 @@
 * Add a `--pub-serve` flag that runs tests against a `pub serve` instance.
   **This feature is only supported on Dart `1.9.2` and higher.**
 
+* When the test runner is killed prematurely, it will clean up its temporary
+  directories and give the current test a chance to run its `tearDown` logic.
+
 ### 0.12.0-beta.4
 
 * Fix a package-root bug.
diff --git a/pubspec.yaml b/pubspec.yaml
index 8f012b0..bafb52b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: test
-version: 0.12.0-dev
+version: 0.12.0-beta.5
 author: Dart Team <misc@dartlang.org>
 description: A library for writing dart unit tests.
 homepage: https://github.com/dart-lang/test