When I "PUT" an object using a pre-signed by localstack S3 URL, the localstack responds with "Content Length: 233" and `<PutObjectResponse>...</PutObjectResponse>` XML in the body. 

When I run the same code against AWS S3, the content length is 0 and response body blank. Would be great if localstack matched the AWS S3 response.

Running the latest 0.9.3 localstack docker image.
bucket_name = 'test-bucket-%s' % short_uid()
        self.s3_client.create_bucket(Bucket=bucket_name)
        
        object_key = 'key-by-hostname'
        self.s3_client.put_object(Bucket=bucket_name, Key=object_key, Body='something')
        url = self.s3_client.generate_presigned_url(
            'get_object', Params={'Bucket': bucket_name, 'Key': object_key}
        )
        
        response = requests.get(url, verify=False)
        self.assertEqual(response.headers['content-type'], 'binary/octet-stream')
        
        self.s3_client.delete_objects(Bucket=bucket_name, Delete={'Objects': [{'Key': object_key}]})
        self.s3_client.delete_bucket(Bucket=bucket_name)
    def test_s3_get_response_content_type_same_as_upload(self):