add missing opam dep

thanks to @kit-ty-kate

Author: c-cube

tiny_httpd.opam

@@ -6,8 +6,8 @@ license: "MIT"
 synopsis: "Minimal HTTP server using good old threads"
 build: [
   ["dune" "build" "@install" "-p" name "-j" jobs]
-  ["dune" "build" "@doc" "-p" name] {with-doc}
-  ["dune" "runtest" "-p" name] {with-test}
+  ["dune" "build" "@doc" "-p" name "-j" jobs] {with-doc}
+  ["dune" "runtest" "-p" name "-j" jobs] {with-test}
 ]
 depends: [
   "dune" { >= "2.0" }
@@ -16,6 +16,7 @@ depends: [
   "odoc" {with-doc}
   "qtest" { >= "2.9" & with-test}
   "qcheck" {with-test & >= "0.9" }
+  "ounit2" {with-test}
 ]
 tags: [ "http" "thread" "server" "tiny_httpd" "http_of_dir" "simplehttpserver" ]
 homepage: "https://github.com/c-cube/tiny_httpd/"