Convert CommonJS exports to ES6-compatible exports

We use `export default` begrudgingly here. Ideally we'd use just `export`, though this entire SDK expects things to be exported as a default. Instead of breaking everything, we'll sacrifice our export pattern for a smaller diff - a later commit can always do the default export -> regular export conversion.

src/components/views/auth/AuthHeader.js

@@ -19,7 +19,7 @@ import React from 'react';
 import createReactClass from 'create-react-class';
 import sdk from '../../../index';
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'AuthHeader',
 
     render: function() {