Fix-up the README example.

Update README.md to use the Cmd module from Cmdliner >= 1.1.0.

Move to cmdliner >= 1.1.0 and update tests accordingly.

Require OCaml >= 4.08, update CI, provide a name for the alcotest test suite to get around Windows filesystem issues.

Merge pull request #50 from pitag-ha/ppxlib.0.25.0-compatibility

Add constraint on cmdliner

Add ppxlib constraint

Stay up-to-date with the PPX ecosystem

Update GitHub Actions workflow to setup-ocaml@v2.

Bump minimum ppxlib version to 0.18.0 to fix #49.

Drop OPAM version field (no longer recommended and flagged by the linter).

Development verison bump.

Remove .travis.yml and update OPAM file.

Drop OCaml 4.04 for ppxlib. Migrate from Travis to GitHub Actions.

Merge pull request #48 from mseri/port_to_ppxlib