testing/ocaml-*: web and database packages

With this, we should have enough OCaml packages to do some interesting projects. This may also be my last OCaml MR with so many commits :)

Off the top of my head, here are some notable OCaml aports according to category:

• network programming: ocamlnet, ocaml-conduit
• event-oriented and reactive programming: ocaml-lwt, ocamlnet, ocaml-react
• GUI: ocaml-labltk, ocaml-lablgtk3
• terminal: ocaml-lambda-term, ocaml-notty, ocaml-curses
• testing frameworks: ocaml-ounit, ocaml-alcotest, ocaml-qcheck
• programmer tools: merlin, ocp-indent, ocp-index, ocaml-omod-bin
• toplevel (REPL) improvements and helpers: utop, ocaml-down, ocaml-omod
• database: ocaml-mariadb, ocaml-postgresql, ocaml-sqlite3 (and the high-level interface: ocaml-caqti)
• HTTP libraries: ocaml-cohttp, ocaml-ocurl (and the easier wrappers: ocaml-ezcurl, ocaml-curly)
• web framework: ocaml-dream
• chat protocols: ocaml-erm_xmpp (Jabber client: jackline), ocaml-irc-client (IRC bot library: ocaml-calculon)
• standard library "extensions": ocaml-containers, ocaml-extlib
• parsers: ocaml-yojson, ocaml-jsonm, ocaml-xmlm, ocaml-markup
• regular expressions: ocaml-pcre, ocaml-re, ocaml-mikmatch
• GitLab console client: ocaml-gitlab-tools

Have fun exploring OCaml :)