prepare for release

Author: kevmoo

CHANGELOG.md

@@ -1,3 +1,11 @@
+## 0.12.20+12
+
+* Now support `v0.30.0` of `pkg/analyzer`
+
+* The test executable now does a "hard exit" when complete to ensure lingering
+  isolates or async code don't block completion. This may affect users trying
+  to use the Dart service protocol or observatory.
+
 ## 0.12.20+11
 
 * Refactor bootstrapping to simplify the test/pub_serve transformer.

pubspec.yaml

@@ -1,5 +1,5 @@
 name: test
-version: 0.12.20+11
+version: 0.12.20+12
 author: Dart Team <[email protected]>
 description: A library for writing dart unit tests.
 homepage: https://github.com/dart-lang/test