Method addEvent

src/almanac.js:33–36

* Adds a success event * @param {Object} event

(event, outcome)

   * @param {Object} event
   */
  addEvent (event, outcome) {
    if (!outcome) throw new Error('outcome required: "success" | "failure"]')
    this.events[outcome].push(event)
  }

  /**
   * retrieve successful events