restrictionRange prop only restricts year, not month

[blakeglucas]

Expected Behavior The restrictionRange prop of the MonthRangePicker component should restrict the selectable range to the months inside restrictionRange.

Actual Behavior The restrictionRange props only restricts year selection.

To Replicate (ES6 via Webpack and Babel)

import MonthRangePicker from 'react-monthrange-picker'
import moment from 'moment'
import 'moment-range'

<MonthRangePicker
  ref={el => this.monthPicker = el}
  direction="bottom"
  onApply={console.log}
  onCancel={console.log}
  onYearChage={console.log}
  onSelect={console.log}
  selectedDateRange={moment.range(moment(), moment())}
  restrictionRange={moment.range(moment().startOf('year'), moment())} />

I don't know if this is by design, but it seems as though the restriction range should apply to the months as well, like react-dates does with days (https://github.com/airbnb/react-dates). Doesn't seem too hard to implement...