We used to throw if event listener is not a function in Stack:

```js
ReactDOM.render(
  <h1 onClick={{}}>Hello World!</h1>,
  document.getElementById('container')
);
```

<img width="565" alt="screen shot 2017-08-08 at 3 41 08 pm" src="https://user-images.githubusercontent.com/810438/29077502-2646412e-7c50-11e7-8c99-3b7f6c0a2589.png">

Fiber silently ignores this.

I think we should throw. This would let us add support for objects (e.g. for passive listener configuration) if we want to in a minor rather than a major.
ReactDOM.render(<div value="foo" />, container);
      expect(nodeValueSetter.mock.calls.length).toBe(1);
      ReactDOM.render(<div value="foo" />, container);
      expect(nodeValueSetter.mock.calls.length).toBe(1);
      ReactDOM.render(<div />, container);
      expect(nodeValueSetter.mock.calls.length).toBe(1);
      ReactDOM.render(<div value={null} />, container);
      expect(nodeValueSetter.mock.calls.length).toBe(1);
      ReactDOM.render(<div value="" />, container);
      expect(nodeValueSetter.mock.calls.length).toBe(2);
      ReactDOM.render(<div />, container);
      expect(nodeValueSetter.mock.calls.length).toBe(2);
    });
    it('should not incur unnecessary DOM mutations for boolean properties', () => {
      var container = document.createElement('div');
      ReactDOM.render(<div checked={true} />, container);
      var node = container.firstChild;
      var nodeValue = true;
      var nodeValueSetter = jest.fn();
      Object.defineProperty(node, 'checked', {
        get: function() {
          return nodeValue;
        },
        set: nodeValueSetter.mockImplementation(function(newValue) {
          nodeValue = newValue;
        }),
      });
      ReactDOM.render(<div checked={true} />, container);
      expect(nodeValueSetter.mock.calls.length).toBe(0);
      ReactDOM.render(<div />, container);