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.
extraAttributeNames.delete(propKey.toLowerCase());
            serverValue = DOMPropertyOperations.getValueForAttribute(
              domElement,
              propKey,
              nextProp,
            );
          }
          if (nextProp !== serverValue) {
            warnForPropDifference(propKey, serverValue, nextProp);
          }
        }
      }
    }
    if (__DEV__) {
      
      if (extraAttributeNames.size > 0) {
        
        warnForExtraAttributes(extraAttributeNames);
      }
    }
    switch (tag) {
      case 'input':
        
        
        inputValueTracking.track((domElement: any));
        ReactDOMFiberInput.postMountWrapper(domElement, rawProps);
        break;
      case 'textarea':