code: function errorFactory (error, status) {
  	/**
  	exported function
  	This function optionnally injects and object into the error response
  	@param {Object}
  	@return {string}
  	*/
  	return function error (obj) {
  		return JSON.stringify(Object.assign({
  			error: error,
  			status: status
  		}, obj));
  	};
  }
docs: internal factory
  @param {string} - the error message that will be caught by API gateway regex
  @param {number} - html error code
  @return {function}