message: Fix error handling in coFetch to return json.error
diff: @@ -65,10 +65,10 @@ const validateStatus = (response, url) => {
  reason = json.message;
  }
  if (!reason) {
  - reason = response.statusText;
  + reason = json.error;
  }
  if (!reason) {
  - reason = json.error;
  + reason = response.statusText;
  }
  const error = new Error(reason);
  error.response = response;
  