React 0.14.7: `<option value="">empty</option>` emits empty string on change
http://jsbin.com/pisita/10/edit?html,js,console,output
React 15.0.0-rc.1`<option value="">empty</option>` emits string with value "empty" on change
http://jsbin.com/bemaze/12/edit?html,js,console,output
This is because React 15.0.0-rc.1 cuts off `value=""` from option tag

case 'button':
        lastProps = ReactDOMButton.getHostProps(this, lastProps);
        nextProps = ReactDOMButton.getHostProps(this, nextProps);
        break;
      case 'input':
        ReactDOMInput.updateWrapper(this);
        lastProps = ReactDOMInput.getHostProps(this, lastProps);
        nextProps = ReactDOMInput.getHostProps(this, nextProps);
        break;
      case 'option':
        lastProps = ReactDOMOption.getHostProps(this, lastProps);
        nextProps = ReactDOMOption.getHostProps(this, nextProps);
        break;
      case 'select':
        lastProps = ReactDOMSelect.getHostProps(this, lastProps);
        nextProps = ReactDOMSelect.getHostProps(this, nextProps);
        break;
      case 'textarea':
        ReactDOMTextarea.updateWrapper(this);
        lastProps = ReactDOMTextarea.getHostProps(this, lastProps);
        nextProps = ReactDOMTextarea.getHostProps(this, nextProps);
        break;
    }
    assertValidProps(this, nextProps);
    this._updateDOMProperties(lastProps, nextProps, transaction);
    this._updateDOMChildren(
      lastProps,
      nextProps,
      transaction,
      context