Use dune-configurator instead of configurator
Use dune-configurator instead of configurator for camlimages to build with dune 2.5.1 and above. The changes have been made based on the guidelines available at https://dune.readthedocs.io/en/stable/dune-libs.html#upgrading-from-the-old-configurator. dune build
and dune test
run fine.