```
        $args = [
            'version' => '2006-03-01',
            'region' => 'eu-west-1',
            'credentials' => CredentialsProvider::get(),
            'http' => ['decode_content' => false],
            'retries' => 6,
            'endpoint' => 'http://localstack:4572',
            'bucket_endpoint' => true
        ];

        $this->client = new S3Client($args);
        $result = $this->client->createBucket([
            'Bucket' => "localbucket",
        ]);
        $buckets = $this->client->listBuckets();
```

$result shows the `@metadata` statusCode as 200 however the returned Location which should tell me where the created bucket is, is an empty string. So it isn't creating the bucket, but I'm getting a 200 response. Just to be sure I run `listBuckets()` and it confirms nothing is being created.

docker-compose.yml settings for localstack:

```
    localstack:
        container_name: localstack
        image: localstack/localstack
        ports:
          - "4567-4593:4567-4593"
          - "${PORT_WEB_UI-8080}:${PORT_WEB_UI-8080}"
        environment:
          - HOSTNAME=pi.docker
          - SERVICES=s3,dynamodb
          - DEFAULT_REGION=eu-west-1
#            - DEBUG=${DEBUG- }
          - DATA_DIR=/tmp/localstack/data
          - PORT_WEB_UI=8080
#            - LAMBDA_EXECUTOR=local
          - DYNAMODB_ERROR_PROBABILITY=0.0
          - DOCKER_HOST=unix:///var/run/docker.sock
        volumes:
          - "${TMPDIR:-/tmp/localstack}:/tmp/localstack"
          - "/var/run/docker.sock:/var/run/docker.sock"
```

Bonus issue: as far as I can tell persistence for s3 doesn't work, I've set DATA_DIR, I've tried changing the volume to `"localstack:/tmp/localstack"` and setting a persisting volume for that. And the directory does persist, however the s3 data isn't stored here so it's reset when taking down the container.
"""Tests for the existence of the specified bucket. Returns the error code
    if the bucket does not exist (200 if the bucket does exist).
    """
    bucket_name = normalize_bucket_name(bucket_name)
    s3_client = aws_stack.connect_to_service('s3')
    try:
        s3_client.head_bucket(Bucket=bucket_name)
    except ClientError as err:
        error_code = err.response.get('Error').get('Code')
        return False, error_code
    return True, 200
def check_content_md5(data, headers):
    actual = md5(strip_chunk_signatures(data))
    expected = headers['Content-MD5']
    try:
        expected = to_str(codecs.encode(base64.b64decode(expected), 'hex'))
    except Exception:
        expected = '__invalid__'
    if actual != expected:
        return error_response('The Content-MD5 you specified was invalid', 'InvalidDigest', status_code=400)
def error_response(message, code, status_code=400):