Fix nix linking

Fix native linking with Nix by building an elf file with dune.

The build bug was introduced by add (modes byte) to bin/dune in order to build a byte-code program for debugging with the ocaml debugger. But this builds only a byte-code program.

The fix replaces (modes byte) with (modes byte exe).

switch back to dynamic linking, but with postInstall overlay

v0.3.1

use dynamic linking

Support custom DNS resolution

v0.3.0

add postInstall to flake.nix

remove ocaml version number

v0.2.7

remove ocaml dependency version number

reduce ocaml dependency version

v0.2.6

reduce ocaml version dependency to >=5.1

use cli args

v0.2.5

take request rate and uri over cli args

add libev present print

v0.2.4

add  print to stdout

build lwt with libev

v0.2.3

add conf-libev to project

alternative flake.nix

v0.2.2

alternative flake.nix

with flake.lock

v0.2.1

add flake.lock