'Upload an image.
image_meta: image metadata as a dictionary
image_data: image data as a object with a read() method
Returns: a tuple of (http response headers, http response body)'

def add_image(self, image_meta, image_data):

    url = '/v1/images'
    headers = self._dict_to_headers(image_meta)
    headers['Content-Type'] = 'application/octet-stream'
    headers['Content-Length'] = int(image_meta['size'])
    response = self._http_request('POST', url, headers, image_data)
    headers = self._header_list_to_dict(response.getheaders())
    LOG.debug('Image    post    done')
    body = response.read()
    return (headers, body)
