notifyCFNThatUploadFailed (error) {
    return notifyCFN.ofFailure({ event: this.event, context: this.context, error })
  }
Uses the cfn-response library to notify CloudFormation that this custom resource failed to do the task it was
invoked to do.

@param {Error|string} error either an error object or a string representing it
@param {Object} event the CFN request object that kicked off this custom resource
@param {Object} context lambda function context

@returns {Promise} a promise representing notifying CFN of completion; return this to the node runtime