chore: fix hotloading of demo

Author: fritz-c

examples/basic-example/app.js

@@ -1,5 +1,5 @@
 import React, { Component } from 'react';
-import SortableTree, { toggleExpandedForAll } from '../../src/index';
+import { SortableTreeWithoutDndContext as SortableTree, toggleExpandedForAll } from '../../src/index';
 import styles from './stylesheets/app.scss';
 import '../shared/favicon/apple-touch-icon.png';
 import '../shared/favicon/favicon-16x16.png';

examples/basic-example/index.js

@@ -1,12 +1,16 @@
 import React from 'react';
 import ReactDOM from 'react-dom';
 import { AppContainer } from 'react-hot-loader'; // eslint-disable-line import/no-extraneous-dependencies
+import { DragDropContext as dragDropContext } from 'react-dnd';
+import HTML5Backend from 'react-dnd-html5-backend';
 
 const rootEl = document.getElementById('app');
 const render = Component => {
+  const wrap = dragDropContext(HTML5Backend);
+  const Wrapped = wrap(Component);
   ReactDOM.render(
     <AppContainer>
-      <Component />
+      <Wrapped />
     </AppContainer>,
     rootEl
   );