createDateArray (start, end) {
    let dates = []
    while (start <= end) {
      dates.push(new Date(start))
      start = this.setDate(new Date(start), this.getDate(new Date(start)) + 1)
    }
    return dates
  }
Creates an array of dates for each day in between two dates.
@param {Date} start
@param {Date} end
@return {Array}