When creating the following bucket notification configuration:
```json
{
    "QueueConfigurations": [
        {
            "Id": "some-id",
            "QueueArn": "arn:aws:sqs:eu-central-1:123456789:my-queue",
            "Events": [
                "s3:ObjectCreated:*"
            ],
            "Filter": {
                "Key": {
                    "FilterRules": [
                        {
                            "Name": "Prefix",
                            "Value": "path/to/folder/"
                        },
                        {
                            "Name": "Suffix",
                            "Value": ".json"
                        }
                    ]
                }
            }
        }
    ]
}
```
and adding some files to S3, I get the following errors from localstack:

```
localstack.services.s3.s3_listener: Unknown filter name: "Prefix"
localstack.services.s3.s3_listener: Unknown filter name: "Suffix"
```

When I change the FilterRule names from "Prefix" to "prefix" and "Suffix" to "suffix", everything works. AWS supports the capitalised name, so this looks like a bug in localstack.
bucket_name = normalize_bucket_name(bucket_name)
    for bucket, notifs in S3_NOTIFICATIONS.items():
        if bucket == bucket_name:
            action = {'PUT': 'ObjectCreated', 'POST': 'ObjectCreated', 'DELETE': 'ObjectRemoved'}[method]
            
            
            if action == 'ObjectCreated' and method == 'POST':
                api_method = 'CompleteMultipartUpload'
            else:
                api_method = {'PUT': 'Put', 'POST': 'Post', 'DELETE': 'Delete'}[method]
            event_name = '%s:%s' % (action, api_method)
            for notif in notifs:
                send_notification_for_subscriber(notif, bucket_name, object_path,
                    version_id, api_method, action, event_name)
def send_notification_for_subscriber(notif, bucket_name, object_path, version_id, api_method, action, event_name):
    bucket_name = normalize_bucket_name(bucket_name)
    if (not event_type_matches(notif['Event'], action, api_method) or
            not filter_rules_match(notif.get('Filter'), object_path)):
        return
    
    message = get_event_message(
        event_name=event_name, bucket_name=bucket_name,
        file_name=urlparse.urlparse(object_path[1:]).path,
        version_id=version_id
    )
    message = json.dumps(message)
    if notif.get('Queue'):