Sirdi deletes other `.ipkg`-files and not just the one(s) it generates

[CodingCellist]

I was playing around with sirdi for an existing project today, and noticed that my .ipkg file (which I was using for interactive editing purposes) was gone. I managed to recover it through git, but it seems sirdi clean removes "*.ipkg" and not just the .ipkg file that it generates itself. It would be nice if sirdi only deleted files it itself had created : )