cuter: use erlangR19 and cleanp expression

It fails to build using R20 and there's no new release available.

pkgs/development/tools/erlang/cuter/default.nix

···
 { stdenv, autoreconfHook, which, writeText, makeWrapper, fetchFromGitHub, erlang
-, beamPackages, z3, python27 }:
+, beamPackages, z3, python }:
 
 stdenv.mkDerivation rec {
   name = "cuter-${version}";
···
     addToSearchPath ERL_LIBS "$1/lib/erlang/lib/"
   '';
 
-  nativeBuildInputs = [ autoreconfHook ];
-  buildInputs = with beamPackages; [ python27.pkgs.setuptools erlang z3.python python27 makeWrapper which ];
+  nativeBuildInputs = [ autoreconfHook makeWrapper which ];
+  buildInputs = [ python python.pkgs.setuptools z3.python erlang ];
 
   buildFlags = "PWD=$(out)/lib/erlang/lib/cuter-${version} cuter_target";
   configurePhase = ''
···
     cp -r * "$out/lib/erlang/lib/cuter-${version}"
     cp cuter "$out/bin/cuter"
     wrapProgram $out/bin/cuter \
-      --prefix PATH : "${python27}/bin" \
-      --suffix PYTHONPATH : "${z3}/lib/python2.7/site-packages" \
+      --prefix PATH : "${python}/bin" \
+      --suffix PYTHONPATH : "${z3}/${python.sitePackages}" \
       --suffix ERL_LIBS : "$out/lib/erlang/lib"
   '';
 

pkgs/top-level/all-packages.nix

···
   inherit (beam.packages.erlang)
     rebar rebar3-open rebar3
     hexRegistrySnapshot fetchHex beamPackages
-    hex2nix cuter;
+    hex2nix;
 
   inherit (beam.packages.erlangR18) relxExe;
+  inherit (beam.packages.erlangR19) cuter;
 
   groovy = callPackage ../development/interpreters/groovy { };