Publish a version matching react-router-redux v5 alpha

[Aaronius]

react-router-redux has a v5 alpha that's incompatible with redux-seamless-immutable. It would be fantastic to have a matching alpha of redux-seamless-immutable that worked with it. One incompatibility I'm aware of is the router reducer of v5 alpha sets location instead of locationBeforeTransitions.

[Aaronius]

Here's the code for routerReducer that's compatible with the v5 alpha of react-router-redux:

import Immutable from 'seamless-immutable';
import { LOCATION_CHANGE } from 'react-router-redux';

const initialState = Immutable({
  location: null
});

export function routerReducer(state = initialState, { type, payload } = {}) {
  if (type === LOCATION_CHANGE) {
    return state.set('location', payload);
  }

  return state;
}

[SoaresMG]

You could open a PR for it