message: fix example in docs
diff: @@ -6,7 +6,6 @@ import { TimePicker, DatePicker } from 'material-ui-pickers';
  export default class BasicUsage extends Component {
  state = {
  selectedDate: moment(),
  - today: new Date(),
  }
  handleDateChange = (date) => {
  @@ -14,7 +13,7 @@ export default class BasicUsage extends Component {
  }
  render() {
  - const { selectedDate, today } = this.state;
  + const { selectedDate } = this.state;
  return (
  <Fragment>
  @@ -26,7 +25,7 @@ export default class BasicUsage extends Component {
  <DatePicker
  keyboard
  clearable
  - maxDate={today}
  + disableFuture
  maxDateMessage="Date must be less than today"
  value={selectedDate}
  onChange={this.handleDateChange}
  