The form POST operation to S3 accepts a `success_action_status` field which can be set to 200/201/204, see [here](https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPOST.html). Localstack currently handles the `success_action_redirect` field [here](https://github.com/localstack/localstack/blob/master/localstack/services/s3/s3_listener.py#L518) and so we should look into handling the `success_action_status` field too.

The 201 from AWS responds with an XML document with some fields about the object that has just been created in AWS, see below.

```
<PostResponse>
    <Location>https://s3.amazonaws.com/link-to-the-file</Location>
    <Bucket>s3-bucket</Bucket>
    <Key>development/8614bd40-691b-4668-9241-3b342c6cf429/image.jpg</Key>
    <ETag>"32-bit-tag"</ETag>
</PostResponse>
```
}
                        result += xmltodict.unparse(dest_dict, full_document=False)
        result += '</NotificationConfiguration>'
        response._content = result
    if method == 'PUT':
        parsed = xmltodict.parse(data)
        notif_config = parsed.get('NotificationConfiguration')
        S3_NOTIFICATIONS[bucket] = []
        for dest in NOTIFICATION_DESTINATION_TYPES:
            config = notif_config.get('%sConfiguration' % (dest))
            configs = config if isinstance(config, list) else [config] if config else []
            for config in configs:
                events = config.get('Event')
                if isinstance(events, six.string_types):
                    events = [events]
                event_filter = config.get('Filter', {})
                
                s3_filter = _get_s3_filter(event_filter)
                if s3_filter and not isinstance(s3_filter.get('FilterRule', []), list):
                    s3_filter['FilterRule'] = [s3_filter['FilterRule']]
                
                notification_details = {
                    'Id': config.get('Id'),
                    'Event': events,
                    dest: config.get(dest),
                    'Filter': event_filter
                }
                S3_NOTIFICATIONS[bucket].append(clone(notification_details))
    return response
class ProxyListenerS3(ProxyListener):