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?
expect(e.getAttribute('foo')).toBe('true');
    });
    itRenders('unknown boolean `false` attributes as strings', async render => {
      const e = await render(<custom-element foo={false} />);
      expect(e.getAttribute('foo')).toBe('false');
    });
    itRenders(
      'no unknown attributes for custom elements with null value',
      async render => {
        const e = await render(<custom-element foo={null} />);
        expect(e.hasAttribute('foo')).toBe(false);
      },
    );
    itRenders(
      'unknown attributes for custom elements using is',
      async render => {
        const e = await render(<div is="custom-element" foo="bar" />);
        expect(e.getAttribute('foo')).toBe('bar');
      },
    );
    itRenders(
      'no unknown attributes for custom elements using is with null value',
      async render => {
        const e = await render(<div is="custom-element" foo={null} />);
        expect(e.hasAttribute('foo')).toBe(false);
      },
    );
  });
});