Relax depdendencies on dune and some other packages.

cduce-types.opam

@@ -29,7 +29,7 @@ build: [
 dev-repo: "git+https://gitlab.math.univ-paris-diderot.fr/cduce/cduce/"
 depends: [
   "ocaml" {>= "4.07.0"}
-  "dune" {build & >= "2.8"}
-  "odoc" {with-doc}
+  "dune" {build & >= "2.7.0"}
+  "odoc" {build & >= "1.5.0"}
   "num"  {>= "1.4"}  
 ]

cduce-types.opam.template

 depends: [
   "ocaml" {>= "4.07.0"}
-  "dune" {build & >= "2.8"}
-  "odoc" {with-doc}
+  "dune" {build & >= "2.7.0"}
+  "odoc" {build & >= "1.5.0"}
   "num"  {>= "1.4"}  
 ]

cduce.opam

@@ -30,11 +30,11 @@ build: [
 dev-repo: "git+https://gitlab.math.univ-paris-diderot.fr/cduce/cduce/"
 depends: [
   "ocaml" {>= "4.07.0"}
-  "dune" {build & >= "2.4"}
+  "dune" {build & >= "2.4.0"}
   "menhir" {build & >= "20181026"}
   "menhirLib" { >= "20181026" }
   "cduce-types" {=  version}
-  "odoc" {with-doc}
+  "odoc" {build & >= "1.5.3"}
   "sedlex" {>= "2.0"}
   ("ocurl" { >= "0.9.1" } |
    "ocamlnet" { >= "4.1.8"})

cduce.opam.template

 depends: [
   "ocaml" {>= "4.07.0"}
-  "dune" {build & >= "2.4"}
+  "dune" {build & >= "2.4.0"}
   "menhir" {build & >= "20181026"}
   "menhirLib" { >= "20181026" }
   "cduce-types" {=  version}
-  "odoc" {with-doc}
+  "odoc" {build & >= "1.5.3"}
   "sedlex" {>= "2.0"}
   ("ocurl" { >= "0.9.1" } |
    "ocamlnet" { >= "4.1.8"})

driver/dune

@@ -25,6 +25,7 @@
  (name cduce_js_top)
  (modules cduce_js_top)
  (libraries cduce-types cduce.lib.js)
+ (optional)
  (modes js)
  (preprocess
   (pps js_of_ocaml-ppx)))