message: Add missing comma in import statement for usage docs
diff: @@ -20,7 +20,7 @@ import DateFnsUtils from "@date-io/date-fns"; // choose your lib
  import {
  DatePicker,
  TimePicker,
  - DateTimePicker
  + DateTimePicker,
  MuiPickersUtilsProvider,
  } from "material-ui-pickers";
  