Migrate some ocurrent Hub images over to the ocaml/ Hub account

[avsm]

Going through the old list of tasks here. There is one item we talked about, moving the https://hub.docker.com/r/ocurrent/opam.ocaml.org images into official ocaml ops account. If we did this a few other services on the ocaml.org deployer could move too.
Out of the things being deployed by the public ocaml.org deployer the two ocaml.org services, watch.ocaml.org, and opam2web aka opam.ocaml.org, might make sense to move all together. The other things like base-image-builder and docs-ci make less sense to change their published image location. What do people think?

Originally posted by @tmcgilchrist in #19 (comment)