**Do you want to request a *feature* or report a *bug*?**
Bug

**What is the current behavior?**
I've started recieving this warning about my SVGs which is using [feGaussianBlur](https://developer.mozilla.org/en-US/docs/Web/SVG/Element/feGaussianBlur): 
`Warning: Expected server HTML to contain a matching <feGaussianBlur> in <filter>.`

**What is the expected behavior?**
Should be no warnings because there are no difference.

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
Such behavior started right after updating to `React 16.0.0-rc.3` and never happened with `React 15.6.1`
expect(e.getAttribute('hidden')).toBe('');
      });
      
      
      
      itRenders('boolean prop with "" value', async render => {
        const e = await render(<div hidden="" />);
        expect(e.getAttribute('hidden')).toBe(null);
      });
      
      itRenders('boolean prop with string value', async render => {
        const e = await render(<div hidden="foo" />);
        expect(e.getAttribute('hidden')).toBe('');
      });
      
      itRenders('boolean prop with array value', async render => {
        const e = await render(<div hidden={['foo', 'bar']} />);
        expect(e.getAttribute('hidden')).toBe('');
      });
      
      itRenders('boolean prop with object value', async render => {
        const e = await render(<div hidden={{foo: 'bar'}} />);
        expect(e.getAttribute('hidden')).toBe('');
      });
      
      itRenders('boolean prop with non-zero number value', async render => {
        const e = await render(<div hidden={10} />);
        expect(e.getAttribute('hidden')).toBe('');
      });