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.
Why? And by that I'm asking: if this isn't the appropriate time for a constant as defined in pep8, what is? You commented on every [constant](http://legacy.python.org/dev/peps/pep-0008/#constants) I defined in this repository.