Update the version number

R=kustermann@google.com

Review URL: https://chromiumcodereview.appspot.com//212163003
diff --git a/pubspec.yaml b/pubspec.yaml
index bb9a13e..ef2c55b 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: protoc-plugin
-version: 0.3.2
+version: 0.3.3
 authors:
 - Dart Team <misc@dartlang.org>
 description: Protoc compiler plugin to generate Dart code