**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/)

<div>
            <input
              ref="a"
              type="radio"
              name="fruit"
              checked={true}
              onChange={emptyFunction}
            />A
            <input
              ref="b"
              type="radio"
              name="fruit"
              onChange={emptyFunction}
            />B
            <form>
              <input
                ref="c"
                type="radio"
                name="fruit"
                defaultChecked={true}
                onChange={emptyFunction}
              />
            </form>
          </div>
        );
      },
    });
    var stub = ReactTestUtils.renderIntoDocument(<RadioGroup />);
    var aNode = ReactDOM.findDOMNode(stub.refs.a);
    var bNode = ReactDOM.findDOMNode(stub.refs.b);