Prop-type rule doesn't work in getInitialState

[tleunen]

I've noticed the rule doesn't work when the props are used in getInitialState.
Here is a test case:

var React = require('react');
React.createClass({
    propTypes: {
        initialValue: React.PropTypes.number
    },

    getDefaultProps: function() {
        return {
            initialValue: 0
        };
    },

    getInitialState: function() {
        return {
            value: this.props.initialValue
        };
    },

    render: function() {
        return null;
    }
});