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.
from botocore.client import ClientError
from requests.models import Response, Request
from localstack import config, constants
from localstack.config import HOSTNAME, HOSTNAME_EXTERNAL
from localstack.utils import persistence
from localstack.utils.aws import aws_stack
from localstack.utils.common import (
    short_uid, timestamp, TIMESTAMP_FORMAT_MILLIS, to_str, to_bytes, clone, md5, get_service_protocol)
from localstack.utils.analytics import event_publisher
from localstack.utils.aws.aws_responses import requests_response
from localstack.services.s3 import multipart_content
from localstack.services.generic_proxy import ProxyListener
S3_NOTIFICATIONS = {}
BUCKET_CORS = {}
BUCKET_LIFECYCLE = {}
LOGGER = logging.getLogger(__name__)
XMLNS_S3 = 'http://s3.amazonaws.com/doc/2006-03-01/'
BUCKET_NAME_REGEX = (r'(?=^.{3,63}$)(?!^(\d+\.)+\d+$)' +
    r'(^(([a-z0-9]|[a-z0-9][a-z0-9\-]*[a-z0-9])\.)*([a-z0-9]|[a-z0-9][a-z0-9\-]*[a-z0-9])$)')
NOTIFICATION_DESTINATION_TYPES = ('Queue', 'Topic', 'CloudFunction', 'LambdaFunction')
OBJECT_METADATA_KEY_PREFIX = 'x-amz-meta-'
ALLOWED_HEADER_OVERRIDES = {
    'response-content-type': 'Content-Type',
    'response-content-language': 'Content-Language',
    'response-expires': 'Expires',
    'response-cache-control': 'Cache-Control',
    'response-content-disposition': 'Content-Disposition',
    'response-content-encoding': 'Content-Encoding',
}
def event_type_matches(events, action, api_method):