* Remove version freeze from urllib3 since upstream bugfix has been released. (See [here](https://github.com/shazow/urllib3/pull/987).)
1.6.0
* Path to cacert.pem has been added to the setup.py, resolving an oversight that led to errors upon SSL requests. * Internal changes to ease future maintenance.
1.5.0
* Add support for publishing push notifications on up to 10 interests.
1.4.0
* Add support for sending push notifications.
1.3.0
* Add support for batch events
1.2.3
* Fixes sharing default mutable argument between requests * Only load RequestsBackend when required (avoids issues on GAE)