support latest csslib

R=jmesserly@google.com

Review URL: https://codereview.chromium.org//1059773002
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d0f5c9e..2562a13 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,9 @@
 This file contains highlights of what changes on each version of the html
 package.
 
+#### Pub version 0.12.0+1
+  * Support `csslib` version `0.12.0`.
+
 #### Rename to package:html 0.12.0
   * package has been renamed to `html`
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 3562da3..0af845a 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,12 +1,12 @@
 name: html
-version: 0.12.1
+version: 0.12.1+1
 author: Dart Team <misc@dartlang.org>
 description: A library for working with HTML documents. Previously known as html5lib.
 homepage: https://github.com/dart-lang/html
 environment:
   sdk: '>=1.2.0 <2.0.0'
 dependencies:
-  csslib: '>=0.10.0 <0.12.0'
+  csslib: '>=0.10.0 <0.13.0'
   source_span: '>=1.0.0 <2.0.0'
   utf: '>=0.9.0 <0.10.0'
 dev_dependencies: