Widen constraints to pick up latest googleapis versions.

lib/src/pubsub_impl.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of gcloud.pubsub;
 
 class _PubSubImpl implements PubSub {
   final http.Client _client;
   final String project;
   final pubsub.PubsubApi _api;
@@ skipping 89 matching lines @@
         ..maxMessages = 1
         ..returnImmediately = returnImmediately;
     return _api.projects.subscriptions.pull(request, subscription);
   }
 
   Future _ack(String ackId, String subscription) {
     var request = new pubsub.AcknowledgeRequest()
         ..ackIds = [ ackId ];
     // The Pub/Sub acknowledge API returns an instance of Empty.
     return _api.projects.subscriptions.acknowledge(
-        request, subscription).then((_) => null);;
+        request, subscription).then((_) => null);
   }
 
   void _checkTopicName(name) {
     if (name.startsWith('projects/') && !name.contains('/topics/')) {
       throw new ArgumentError(
           "Illegal topic name. Absolute topic names must have the form "
           "'projects/[project-id]/topics/[topic-name]");
     }
     if (name.endsWith('/topics/')) {
       throw new ArgumentError(
@@ skipping 349 matching lines @@
   Future<Page<Subscription>> next({int pageSize}) {
     if (_nextPageToken == null) return new Future.value(null);
     if (pageSize == null) pageSize = this._pageSize;
 
     return _api._listSubscriptions(
         _topic, pageSize, _nextPageToken).then((response) {
       return new _SubscriptionPageImpl(_api, _topic, pageSize, response);
     });
   }
 }