message: Fix MuiPickersUtilsProvider tests
diff: import React from 'react';
  -import { shallow } from '../test-utils';
  +import { shallow } from 'enzyme'; // required to use just shallow here because utils prop override
  import DateFnsUtils from '../../src/utils/date-fns-utils';
  import MuiPickersUtilsProvider from '../../src/utils/MuiPickersUtilsProvider';
  