To work with blob need pass headers "Content-Type: application/octet-stream".
Method "self._check_artifact_put" for the send request PUT does
not support headers. It does not allow testing work with a blob.
So added ability to specify headers in PUT/PATCH request.
Change-Id: I3c832ef732d707eb93615a5ffb6f3f8debfbcd99
Closes-bug: #1490306