[fix] attempt to avoid need for 'Array.from' polyfill

Fix #409

docs/guides/getting-started.md

@@ -1,5 +1,8 @@
 # Getting started
 
+It is recommended that your application provide a `Promise` and `Array.from`
+polyfill.
+
 ## Webpack and Babel
 
 [Webpack](webpack.js.org) is a popular build tool for web apps. Below is an

src/modules/NativeMethodsMixin/index.js

@@ -69,7 +69,7 @@ const NativeMethodsMixin = {
   setNativeProps(nativeProps: Object) {
     // DOM state
     const node = findNodeHandle(this);
-    const classList = [...node.classList];
+    const classList = Array.prototype.slice.call(node.classList);
 
     const domProps = createDOMProps(nativeProps, style =>
       StyleRegistry.resolveStateful(style, classList)