react-sortable-tree not working with react-froala-wysiwyg

Hi!

When using react-sortable-tree with another drag-n-drop component like react-froala-wysiwyg the tree work as expected but the drag-n-drop in react-froala-wysiwyg is blocked.

Here are the steps to create a project with the issue:
> npm install -g react-create-app
> react-create-app sortable_tree_and_froala
> cd sortable_tree_and_froala
> npm install --save react-sortable-tree react-froala-wysiwyg

Replace the index.js content with this:

```
import React from 'react';
import { render } from 'react-dom';
import './index.css';
import registerServiceWorker from './registerServiceWorker';

import Tree from 'react-sortable-tree'
import FroalaEditor from 'react-froala-wysiwyg';
import 'font-awesome/css/font-awesome.css';
import 'froala-editor/js/froala_editor.pkgd.min.js';
import 'froala-editor/css/froala_style.min.css';
import 'froala-editor/css/froala_editor.pkgd.min.css';
import $ from 'jquery';
window.$ = $;

const App = () => (

render(, document.getElementById('root'));
```

Now if you run "npm start" and insert an image in the Froala editor it cannot be dragged and dropped to another location in the editor window.

I understand if interoperability issues are not really something you look into so feel free to close this issue if that is the case.