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/structures/auth/ForgotPassword.js

@@ -40,7 +40,7 @@ const PHASE_EMAIL_SENT = 3;
 // User has clicked the link in email and completed reset
 const PHASE_DONE = 4;
 
-module.exports = createReactClass({
+export default createReactClass({
     displayName: 'ForgotPassword',
 
     propTypes: {