adding with `opam pin`

[idkjs]

Adding with opam pin add re-web produces the following:

❯ opam pin add re-web https://github.com/yawaramin/re-web.git
Package re-web does not exist, create as a NEW package? [Y/n] y
[re-web.~dev] synchronised (git+https://github.com/yawaramin/re-web.git)
[ERROR] In
        /Users/mando/Github/opium-realworld-example-app/_opam/.opam-switch/sources/re-web/re-web.opam:
        unsupported or missing file format version; should be 2.0
        or older [skipped]

[ERROR] Invalid opam file in re-web source from
        git+https://github.com/yawaramin/re-web.git:
    error  2: File format error: unsupported or missing file
              format version; should be 2.0 or older

might have to update something. Just an FYI.

[yawaramin]

Hi boss, duplicate of #34 :-)