Its a common standard of PHP to not use the closing tag. The reasons for this are many but mainly to avoid whitespace problems with headers.
PSR-1 and PSR-2 have been accepted and they rule over this, would be good to check them:
I've checked that out and I'd love to hear more about the reasons where can I read more about that?
@rdohms do you know any tool that helps doing this?
A simple find and replace should do in this case.