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.
This is possible too but why not:

```
def airbrake_error_from_record(record):
  return {
    'notifier': {
      'name': 'airbrake-python'
      'version': __version__,
      'url': __url__,
    },
    ...
  }
```

This way all this knowledge is grouped in 1 function.