Fix itms links under iOS

Does what it says on the tin. Actually send the `itms-services` link so iOS can download the OTA build.
The router class just decides what class & method to route a request to with the params passed into it - it doesn't have knowledge of platforms or any of the rendering code. This is probably (unless we abstract out further) the best place for this at the moment. As it stands the app works as such:

Index.php (Entry point)
 |
V
Router.php (Routing to various classes throughout the app depending on URL request)
 |
V
Main.php (Model class that responds to methods invoked from the router, fetches data & returns up the chain)
 |
V
Renderer.php (Probably the closest to a View Controller we have here - takes data, gives it to view classes, renders output)