Prepare for 0.13.1 release

R=jakemac@google.com

Review URL: https://codereview.chromium.org//554813002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/observe@39995 260f80e4-7a28-3924-810f-c04153c831b5
diff --git a/CHANGELOG.md b/CHANGELOG.md
index cdd9d37..6e8a55c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-#### 0.12.1-dev
+#### 0.12.1
   * Upgraded error messages to have a unique and stable identifier.
 
 #### 0.12.0
diff --git a/pubspec.yaml b/pubspec.yaml
index 26151a7..aa5bdb8 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: observe
-version: 0.12.1-dev
+version: 0.12.1
 author: Polymer.dart Authors <web-ui-dev@dartlang.org>
 description: >
   Observable properties and objects for use in template_binding.
@@ -17,7 +17,7 @@
   source_maps: '>=0.9.4 <0.11.0'
   source_span: '>=1.0.0 <2.0.0'
   utf: '>=0.9.0 <0.10.0'
-  code_transformers: '>=0.2.3-dev <0.3.0'
+  code_transformers: '>=0.2.3 <0.3.0'
 dev_dependencies:
   unittest: '>=0.10.0 <0.11.0'
   stack_trace: '>=1.0.2 <2.0.0'