**Do you want to request a _feature_ or report a _bug_?**
Bug
**What is the current behavior?**
React at the beginning rounds `input[type=range]` value to 0 or 1, and then looks at step parameter which is 0.1 for example. The result is incorrect value of input after component mounts. When I put `value` attribute after `step` attributes, it works fine.
**If the current behavior is a bug, please provide the steps to reproduce and if possible a minimal demo of the problem via https://jsfiddle.net or similar (template: https://jsfiddle.net/reactjs/69z2wepo/).**
Demo: https://jsfiddle.net/2Lm4gy5k/ Comment or uncomment line 13 and 14 to see the difference.

**What is the expected behavior?**
To always look at step parameter and then round the value (if required).
**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
v15.1.0 (Opera, Chrome, Firefox). 

Yes, works in v.0.14.0 (https://jsfiddle.net/wrcnLugd/)

var node = container.firstChild;
    var nodeValue = 'a';
    var nodeValueSetter = jest.genMockFn();
    Object.defineProperty(node, 'value', {
      get: function() {
        return nodeValue;
      },
      set: nodeValueSetter.mockImplementation(function(newValue) {
        nodeValue = newValue;
      }),
    });
    ReactDOM.render(<input value="a" />, container);
    expect(nodeValueSetter.mock.calls.length).toBe(0);
    ReactDOM.render(<input value="b"/>, container);
    expect(nodeValueSetter.mock.calls.length).toBe(1);
  });
  it('should properly control a value of number `0`', function() {
    var stub = <input type="text" value={0} onChange={emptyFunction} />;
    stub = ReactTestUtils.renderIntoDocument(stub);
    var node = ReactDOM.findDOMNode(stub);
    node.value = 'giraffe';
    ReactTestUtils.Simulate.change(node);
    expect(node.value).toBe('0');
  });
  it('should have the correct target value', function() {
    var handled = false;
    var handler = function(event) {
      expect(event.target.nodeName).toBe('INPUT');
      handled = true;
    };