* ocaml-version: 3.1.0 -> 3.4.0
* ocamlformat: 0.19.0 -> 0.20.0
* odoc-parser: refactor use version variable
use version to compute the uri for the archive
* odoc-parser: 0.9.0 -> 1.0.0
* odoc-parser: allow multiple versions
allow both 0.9.0 and 1.0.0 to accommodate different version of
ocamlformat
* ocamlformat: 0.20.0 -> 0.20.1
