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

return <div>{props.test}</div>;
    }
    Child.defaultProps = {test: 2};
    Child.propTypes = {test: React.PropTypes.string};
    spyOn(console, 'error');
    ReactTestUtils.renderIntoDocument(<Child />);
    expect(console.error.argsForCall.length).toBe(1);
    expect(
      console.error.argsForCall[0][0].replace(/\(at .+?:\d+\)/g, '(at **)')
    ).toBe(
      'Warning: Failed prop type: Invalid prop `test` of type `number` ' +
      'supplied to `Child`, expected `string`.\n' +
      '    in Child (at **)'
    );
  });
  it('should receive context', function() {
    var Parent = React.createClass({
      childContextTypes: {
        lang: React.PropTypes.string,
      },
      getChildContext: function() {
        return {lang: 'en'};
      },
      render: function() {
        return <Child />;
      },
    });
    function Child(props, context) {