Use createElement rather than createFactory in react-dom-factories

This is a tiny bit more future-proof.

packages/react-dom-factories/index.js

@@ -37,7 +37,15 @@
   /**
    * Create a factory that creates HTML tag elements.
    */
-  var createDOMFactory = React.createFactory;
+  function createDOMFactory(type) {
+    var factory = React.createElement.bind(null, type);
+    // Expose the type on the factory and the prototype so that it can be
+    // easily accessed on elements. E.g. `<Foo />.type === Foo`.
+    // This should not be named `constructor` since this may not be the function
+    // that created the element, and it may not even be a constructor.
+    factory.type = type;
+    return factory;
+  };
 
   /**
    * Creates a mapping from supported HTML tags to `ReactDOMComponent` classes.