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/rooms/MemberList.js

@@ -32,7 +32,7 @@ const INITIAL_LOAD_NUM_MEMBERS = 30;
 const INITIAL_LOAD_NUM_INVITED = 5;
 const SHOW_MORE_INCREMENT = 100;
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'MemberList',
 
     getInitialState: function() {