shows the assets on iOS

[hanwencheng]

close #364

If any new static files like images and is required in the JS codebase, if order to link these static files to bundle for iOS devices, we need run yarn build-prod:ios in order to generate the updated assets folder.

Reason:
Images cannot be find in the release bundle, need to:

1. extract the required static assets into ios/assets folder.
2. add the references to ios/assets folder in Xcode

[Tbaut]

This is awesome that you found the problem. Since I couldn't reproduce, I'll let @yjkimjunior confirm.

[pmespresso]

please revert the change in AppDelegate.m

other than that, I am able to see the logo and back button 👍