V1.1.0 updates

Some long needed updates. Improves usability and leverages more of the datapoints available through the airbrake error reporting API. Includes a helper for fetching a logger object, pre-configured with an AirbrakeHandler, and many other improvements.

Updated [the README](https://github.com/samstav/airbrake-python/blob/v1.1.0/README.md) to reflect the simplified interface.
Maybe the better question is, am I doing the wrong thing here? Maybe, if a user knows what they're doing and they have set auto-notify to False, and choose to create a handler with that Airbrake instance, then they should be allowed to do that. That is probably the right way to go. I could then add a method to the handler, `notify()`, which would allow you to ship your aggregated errors from your Handler.