Update README.md (#80)

* Update README.md

Just adding information about avoiding Administration Operations Limits errors

* Update README.md

correct key name

Author: andreladocruz

README.md

@@ -34,9 +34,15 @@ You can check [Google Cloud PubSub client](http://googleapis.github.io/google-cl
     'retries' => 3,
     'request_timeout' => 60,
     'subscriber' => 'subscriber-name',
+    'create_topics' => true,
+    'create_subscriptions' => true,
 ],
 ```
 
+## Avoiding Administrator Operations Limits
+
+To avoid limit issues, change the `create_topics` and `create_subscriptions` flags to false.
+
 ## Testing
 
 You can run the tests with :