Replacing native functions should be avoided

Created by: felixsanz

In the case of: 10. Immutable Redux, I can see this:

import { Map } from 'immutable';
import { MAKE_BARK } from '../actions/dog-actions';

const initialState = Map({
  hasBarked: false,
});

Isn't a bad practice to replace Map (which is native) with the Map version from Immutable?

I think it's better idea to just import Immutable and use Immutable.Map().

Do you accept PR for this?