Upgrade googleapis constraint (#192)

CHANGELOG.md

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7612b0e..0407ec8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+## 0.8.13
+- Support the latest version `^13.0.0` of the `googleapis` package.
+
 ## 0.8.12
 - Support the latest version 12.0.0 of the `googleapis` package.
 

pubspec.yaml

diff --git a/pubspec.yaml b/pubspec.yaml
index b02ccb4..b315607 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: gcloud
-version: 0.8.12
+version: 0.8.13
 description: >-
   High level idiomatic Dart API for Google Cloud Storage, Pub-Sub and Datastore.
 repository: https://github.com/dart-lang/gcloud
@@ -13,7 +13,7 @@
 
 dependencies:
   _discoveryapis_commons: ^1.0.0
-  googleapis: '>=3.0.0 <13.0.0'
+  googleapis: '>=3.0.0 <14.0.0'
   http: '>=0.13.5 <2.0.0'
   meta: ^1.3.0
   retry: ^3.1.1