title: React-intl and react-router: formatRelative problems
body: <p>I am using react-router (0.13) with react-intl (1.2.0). I have this in routes:</p>
  
  <pre><code>var i18n = {
      locales: ['en-US']
  };
  
  var routes = (
      &lt;Route name='home' path='/' handler={App}&gt;
      &lt;/Route&gt;
  );
  
  Router.run(routes, function (Handler) {
      React.render(&lt;Handler locales={i18n.locales} /&gt;, document.body);
  });
  </code></pre>
  
  <p>And this in App:</p>
  
  <pre><code>var ReactIntl = require('react-intl');
  var IntlMixin = ReactIntl.IntlMixin;
  var FormattedRelative = ReactIntl.FormattedRelative;
  
  var App = React.createClass({
      mixins: [IntlMixin],
  
      render: function() {
  
          var postDate = Date.now() - (1000 * 60 * 60 * 24);
          var foo = this.formatRelative(postDate); //this worked before updating to 1.2.0
  
          return (
              {foo}
              &lt;FormattedRelative value={postDate}/&gt;
          );
      }
  });
  </code></pre>
  
  <p>Both imperative call (this.formatRelative) and component use of formatRelative fail with this: 'A message must be provided as a String or AST.'</p>
  
  <p>What I am doing wrong?</p>