Remove duniverse rules from the Makefile

This removes seemingly outdated rules and make the Makefile more
readable and usable as documentation.

Makefile

@@ -1,15 +1,6 @@
-ifeq "$(wildcard dune-local/dune.exe)" ""
-  DUNE = dune
-	DUNE_BUILD_TARGET =
-else
-  DUNE = dune-local/dune.exe
-	DUNE_BUILD_TARGET = odoc.install
-endif
-DUNE_ARGS ?=
-
 .PHONY : build
 build :
-	$(DUNE) build $(DUNE_ARGS) $(DUNE_BUILD_TARGET)
+	dune build
 
 .PHONY : publish-docs
 publish-docs:
@@ -19,114 +10,16 @@ publish-docs:
 	rsync -av _build/default/doc/html/odoc/ .
 
 .PHONY : test
-test : build
-	$(DUNE) runtest $(DUNE_ARGS)
+test :
+	dune runtest
 
 .PHONY : coverage
 coverage :
-	$(DUNE) build $(DUNE_ARGS) --instrument-with bisect_ppx @test/runtest --no-buffer -j 1 --force || true
+	dune build --instrument-with bisect_ppx @test/runtest --no-buffer -j 1 --force || true
 	bisect-ppx-report html
 	@echo See _coverage/index.html
 
 .PHONY : clean
 clean :
-	$(DUNE) clean
-	rm -rf $(COVERAGE)
-
-DUNIVERSE_DEPS = astring cmdliner cppo fmt fpath ocaml-re result tyxml uutf
-ASTRING_VERSION = v0.8.4
-CMDLINER_VERSION = v1.0.4
-CPPO_VERSION = v1.6.6
-DUNE_VERSION = 2.6.2
-FMT_VERSION = v0.8.8
-FPATH_VERSION = v0.7.2
-OCAML_RE_VERSION = 1.9.0
-RESULT_VERSION = 1.5
-TYXML_VERSION = 4.4.0
-UUTF_VERSION = v1.0.2
-
-GIT_CHECKOUT = git -c advice.detachedHead=false checkout
-
-.PHONY : duniverse
-duniverse : $(addsuffix /dune-project,$(DUNIVERSE_DEPS)) dune-local/dune.exe
-
-dune-local/dune.exe : dune-local
-	cd dune-local ; ocaml bootstrap.ml
-
-astring :
-	git clone https://github.com/dbuenzli/astring.git -n -o upstream
-	cd astring ; $(GIT_CHECKOUT) $(ASTRING_VERSION)
-
-cmdliner :
-	git clone https://github.com/dbuenzli/cmdliner.git -n -o upstream
-	cd cmdliner ; $(GIT_CHECKOUT) $(CMDLINER_VERSION)
-
-cppo :
-	git clone https://github.com/ocaml-community/cppo.git -n -o upstream
-	cd cppo ; $(GIT_CHECKOUT) $(CPPO_VERSION)
-
-dune-local :
-	git clone https://github.com/ocaml/dune.git -n -o upstream dune-local
-	cd dune-local ; $(GIT_CHECKOUT) $(DUNE_VERSION)
-
-fmt :
-	git clone https://github.com/dbuenzli/fmt.git -n -o upstream
-	cd fmt ; $(GIT_CHECKOUT) $(FMT_VERSION)
-
-fpath :
-	git clone https://github.com/dbuenzli/fpath.git -n -o upstream
-	cd fpath ; $(GIT_CHECKOUT) $(FPATH_VERSION)
-
-ocaml-re :
-	git clone https://github.com/ocaml/ocaml-re.git -n -o upstream
-	cd ocaml-re ; $(GIT_CHECKOUT) $(OCAML_RE_VERSION)
-
-result :
-	git clone https://github.com/janestreet/result.git -n -o upstream
-	cd result ; $(GIT_CHECKOUT) $(RESULT_VERSION)
-
-tyxml :
-	git clone https://github.com/ocsigen/tyxml.git -n -o upstream
-	cd tyxml ; $(GIT_CHECKOUT) $(TYXML_VERSION)
-
-uutf :
-	git clone https://github.com/dbuenzli/uutf.git -n -o upstream
-	cd uutf ; $(GIT_CHECKOUT) $(UUTF_VERSION)
-
-astring/dune-project : astring
-	mv $</opam $</$<.opam
-	echo '(lang dune 1.0)' > $@; \
-  echo '(name $<)' >> $@; \
-  echo '(library (name $<)(public_name $<)(modules :standard \ astring_top astring_top_init)(flags :standard -w -27)(wrapped false))' > $</src/dune
-
-cmdliner/dune-project: cmdliner
-
-cppo/dune-project: cppo
-
-fmt/dune-project : fmt
-	mv $</opam $</$<.opam
-	echo '(lang dune 1.0)' > $@; \
-  echo '(name $<)' >> $@; \
-  echo '(library (name $<)(public_name $<)(modules fmt)(flags :standard -w -3-6-27-34-50)(wrapped false))' > $</src/dune
-
-fpath/dune-project : fpath
-	mv $</opam $</$<.opam
-	echo '(lang dune 1.0)' > $@; \
-  echo '(name $<)' >> $@; \
-  echo '(library (name $<)(public_name $<)(libraries astring result)(modules fpath)(flags :standard -w -6-27-32-33-39)(wrapped false))' > $</src/dune
-
-ocaml-re/dune-project: ocaml-re
-
-result/dune-project: result
-
-tyxml/dune-project: tyxml
-
-uutf/dune-project : uutf
-	mv $</opam $</$<.opam
-	echo '(lang dune 1.0)' > $@; \
-  echo '(name $<)' >> $@; \
-  echo '(library (name $<)(public_name $<)(flags (:standard -w -3-27))(wrapped false))' > $</src/dune
-
-.PHONY : distclean
-distclean :
-	rm -rf $(DUNIVERSE_DEPS) dune-local
+	dune clean
+	rm -r _coverage