prepare for 0.5.3+2

Author: kevmoo

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.5.3+2
+
+* Resolved a strong-mode error.
+
 ## 0.5.3+1
 
 * Performance: Avoid excessive cloning in merge.

pubspec.yaml

@@ -1,7 +1,7 @@
 name: protobuf
-version: 0.5.3+1
+version: 0.5.3+2
 author: Dart Team <[email protected]>
-description: Runtime library for protobuf support.
+description: Runtime library for protocol buffers support.
 homepage: https://github.com/dart-lang/protobuf
 environment:
   sdk: '>=1.13.0 <2.0.0'