title: Issue converting from Swift 2 to Swift 3 in Xcode 8
body: <p>So I updated to Xcode 8 and when prompted to convert my source code to Swift 3 I said yes. I forget what I did after that, but for some reason my code is back to the way it was. Now when I try to convert it again, Xcode tells me that i already converted it so I cannot do it again. Is there any way to reset this convert feature or trick it to convert again?</p>