Testing apps for iOS 5.1 in Xcode 7

Since my upgrade to Xcode 7, i cannot longer use my first gen iPad (iOS 5.1.1) for testing. I still have an old Macbook Pro laying around with Xcode 4 installed. But since Xcode 7, i cannot convert a project to open properly in anything under Xcode 5.1

This is problematic, because i developed a company app that runs on a bunch of first gen ipads, but also some ipads with more recent iOS versions.

Is there a way to solve this ? Something that allows me to test my app in iOS versions 5.1 to 9 (with xcode 7) ?