drop publish: none (#9)

diff --git a/pubspec.yaml b/pubspec.yaml
index eca05dd..52041ff 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,5 @@
 name: sync_http
 version: 0.2.0
-publish_to: none
 author: Dart Team <misc@dartlang.org>
 description: Synchronous HTTP client for Dart.
 homepage: https://github.com/dart-lang/sync_http