Pjino

I was thinking `composite`.

Thank you! Maybe if you would put this in README you wouldn't be bothered anymore by someone asking for `composite` feature... :)

Well, after a few attempts I wasn't able to make any `image_operator()` commands work. For example, ``` image = open(Path.absname("priv/static/uploads/45992.png")) image_operator(image, "convert -resize: 50% ") |> create(in_place: true) ``` doesn't...