more serious testing

[c-cube]

maybe depend on conf-curl/ocurl/curly to do the tests?

• test gzip decoding (upload with compression enabled?)
• test gzip encoding (see echo.ml and /zcat/file endpoint)
• test routing
• have a stupid middleware to instrument stats, do 10k calls, see if the stats match expectations
• have a stupid middleware that adds a header to response (X-tested: ok?)

for gzip: we can use a select expression in dune, to avoid a hard dependency on it.

[craff]

And you can assign me to this task (i you want), I will need the same test for simple_httpd like the one for my PR #50 which
is not very necessary for tiny_httpd compared to simple_httpd.

[craff]

Do you mind if http_of_dir move to the tiny_httpd_camlzip package to have a compress option. This would
give a simple way to test compression and also allow more use case of http_of_dir.

[c-cube]

I think we can keep http_of_dir in the tiny_httpd package, but use the select expression in dune to have an optional dep on tiny_httpd_camlzip. I can give more details on how that works.

[craff]

Yes please, if you can give me details, I could use them for Simple_httpd too.
I have ssl support (was easy to do with ocaml-ssl), but it is not easy to separate, the easiest would be to have a fake SSl module with the same interface. But I struggle with opam to do that. Ideally, I would like opam option to refer to separate git branch if possible.