removed challenge payload that is no longer needed in new acme spec

acme_tiny.py

@@ -139,8 +139,7 @@ def get_crt(account_key, csr, acme_dir, log=LOGGER, CA=DEFAULT_CA, disable_check
             raise ValueError("Wrote file to {0}, but couldn't download {1}: {2}".format(wellknown_path, wellknown_url, e))
 
         # say the challenge is done
-        challenge_payload = {"keyAuthorization": keyauthorization}
-        _send_signed_request(challenge['url'], challenge_payload, "Error submitting challenges: {0}".format(domain))
+        _send_signed_request(challenge['url'], {}, "Error submitting challenges: {0}".format(domain))
         authorization = _poll_until_not(auth_url, ["pending"], "Error checking challenge status for {0}".format(domain))
         if authorization['status'] != "valid":
             raise ValueError("Challenge did not pass for {0}: {1}".format(domain, authorization))