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.
>We have already seen the benefit of that in our project

It looks like you misunderstand how API works. Which is our fault and we are trying to ship better docs.

Anyway it looks like you think that `errors: []` means that you can send multiple errors in one HTTP request. That is wrong. We allowed sending multiple errors in that API to support exceptions chaining: http://legacy.python.org/dev/peps/pep-3134/ . So for example:

```
raise exc2 from exc
```

will be turned into:

```
{
  errors: [exc2, exc1]
}
```

But from the Airbrake perspective that will be one error. So when you use `auto_notify=False` and send JSON like:

{
    errors: [exc1, exc2, exc3, exc4, exc5],
}

Airbrake will process that JSON as single exception which is not what you want. That is why I suggest to remove `auto_notify` option.