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.
append_cors_headers(bucket_name, request_method=method, request_headers=headers, response=response)
            append_last_modified_headers(response=response)
            response_content_str = None
            try:
                response_content_str = to_str(response._content)
            except Exception:
                pass
            
            
            
            
            if response_content_str and response_content_str.startswith('<'):
                is_bytes = isinstance(response._content, six.binary_type)
                append_last_modified_headers(response=response, content=response_content_str)
                
                response._content = re.sub(r'([^\?])>\n\s*<', r'\1><', response_content_str, flags=re.MULTILINE)
                
                response._content = self._update_location(response._content, bucket_name)
                
                if is_bytes:
                    response._content = to_bytes(response._content)
                
                
                if 'text/html' in response.headers.get('Content-Type', ''):
                    response.headers['Content-Type'] = 'application/xml; charset=utf-8'
                response.headers['content-length'] = len(response._content)
            
            if method == 'DELETE':
                response.headers['content-length'] = len(response._content)
    def _update_location(self, content, bucket_name):