When setting boolean attributes on Web Components
`<x-search somebool name={this.props.name} />`
they get rendered as attribute/value pairs instead
`<x-search somebool="true" name={this.props.name}>`

This causes problems with some AMP components, for eg. `<amp-iframe />` which has a `resizable` attribute that gets rendered as `resizable="true"`. This results in non valid AMP content and developers crying with blood tears on their keyboards :)
> The attribute 'resizable' in tag 'amp-iframe' is set to the invalid value 'true'. (see https://www.ampproject.org/docs/reference/components/amp-iframe)

Is there any reason for the current behaviour? Will changing this break something else?
const el = container.firstChild;
      expect(el.hasAttribute('whatever')).toBe(false);
    });
    it('warns on bad casing of known HTML attributes', function() {
      let el;
      expect(() => {
        el = ReactTestUtils.renderIntoDocument(<div SiZe="30" />);
      }).toErrorDev(
        'Warning: Invalid DOM property `SiZe`. Did you mean `size`?',
      );
      expect(el.getAttribute('size')).toBe('30');
    });
  });
  describe('Object stringification', function() {
    it('allows objects on known properties', function() {
      const el = ReactTestUtils.renderIntoDocument(<div acceptCharset={{}} />);
      expect(el.getAttribute('accept-charset')).toBe('[object Object]');
    });
    it('should pass objects as attributes if they define toString', () => {
      const obj = {
        toString() {
          return 'hello';
        },
      };
      const container = document.createElement('div');
      ReactDOM.render(<img src={obj} />, container);
      expect(container.firstChild.src).toBe('http://localhost/hello');
      ReactDOM.render(<svg arabicForm={obj} />, container);
      expect(container.firstChild.getAttribute('arabic-form')).toBe('hello');
      ReactDOM.render(<div unknown={obj} />, container);