updated to current opam-2.0.3, which is also the version provided by Cygwin 3.0.4;
This is OPAM 2.0.3 -- the OCaml Package Manager.
The executables for x86_64-linux and x86_64-darwin are from
https://github.com/ocaml/opam/releases/tag/2.0.3
The executable for x86_64-cygwin is provided as a Cygwin package.
Makarius
21-Mar-2018