*feature*

>Warning: A component is `contentEditable` and contains `children` managed by React. It is now your responsibility to guarantee that none of those nodes are unexpectedly modified or duplicated. This is probably not intentional.

It would help heaps if I would know _which_ component is causing this.
it('should remove properties', () => {
      var container = document.createElement('div');
      ReactDOM.render(<div className="monkey" />, container);
      expect(container.firstChild.className).toEqual('monkey');
      ReactDOM.render(<div />, container);
      expect(container.firstChild.className).toEqual('');
    });
    it('should properly update custom attributes on custom elements', () => {
      var container = document.createElement('div');
      ReactDOM.render(<some-custom-element foo="bar" />, container);
      ReactDOM.render(<some-custom-element bar="buzz" />, container);
      var node = container.firstChild;
      expect(node.hasAttribute('foo')).toBe(false);
      expect(node.getAttribute('bar')).toBe('buzz');
    });
    it('should clear a single style prop when changing `style`', () => {
      var styles = {display: 'none', color: 'red'};
      var container = document.createElement('div');
      ReactDOM.render(<div style={styles} />, container);
      var stubStyle = container.firstChild.style;
      styles = {color: 'green'};
      ReactDOM.render(<div style={styles} />, container);
      expect(stubStyle.display).toEqual('');
      expect(stubStyle.color).toEqual('green');
    });
    it('should reject attribute key injection attack on markup', () => {
      spyOn(console, 'error');
      for (var i = 0; i < 3; i++) {
        var container = document.createElement('div');
        var element = React.createElement(