Adding webpack code splitting (#3377)

webapp/actions/channel_actions.jsx

@@ -1,7 +1,7 @@
 // Copyright (c) 2016 Mattermost, Inc. All Rights Reserved.
 // See License.txt for license information.
 
-import {browserHistory} from 'react-router';
+import {browserHistory} from 'react-router/es6';
 import * as Utils from 'utils/utils.jsx';
 import TeamStore from 'stores/team_store.jsx';
 import UserStore from 'stores/user_store.jsx';

webapp/actions/global_actions.jsx

@@ -20,7 +20,7 @@ import * as I18n from 'i18n/i18n.jsx';
 
 import {trackPage} from 'actions/analytics_actions.jsx';
 
-import {browserHistory} from 'react-router';
+import {browserHistory} from 'react-router/es6';
 
 import en from 'i18n/en.json';
 

webapp/actions/team_actions.jsx

@@ -10,7 +10,7 @@ import * as AsyncClient from 'utils/async_client.jsx';
 import Client from 'utils/web_client.jsx';
 import AppDispatcher from 'dispatcher/app_dispatcher.jsx';
 
-import {browserHistory} from 'react-router';
+import {browserHistory} from 'react-router/es6';
 
 export function checkIfTeamExists(teamName, onSuccess, onError) {
     Client.findTeamByName(teamName, onSuccess, onError);

webapp/actions/websocket_actions.jsx

@@ -18,7 +18,7 @@ import * as GlobalActions from 'actions/global_actions.jsx';
 import Constants from 'utils/constants.jsx';
 const SocketEvents = Constants.SocketEvents;
 
-import {browserHistory} from 'react-router';
+import {browserHistory} from 'react-router/es6';
 
 const MAX_WEBSOCKET_FAILS = 7;
 const WEBSOCKET_RETRY_TIME = 3000;