python.pkgs.acme: move to separate expression

pkgs/development/python-modules/acme/default.nix

@@ -0,0 +1,19 @@
+{ stdenv, buildPythonPackage, fetchPypi
+, certbot, nose, cryptography, pyasn1, pyopenssl, pyRFC3339
+, pytz, requests, six, werkzeug, mock, ndg-httpsclient }:
+
+buildPythonPackage rec {
+  inherit (certbot) src version;
+
+  pname = "acme";
+  name = "${pname}-${version}";
+
+  propagatedBuildInputs = [
+    cryptography pyasn1 pyopenssl pyRFC3339 pytz requests six werkzeug mock
+    ndg-httpsclient
+  ];
+
+  buildInputs = [ nose ];
+
+  postUnpack = "sourceRoot=\${sourceRoot}/acme";
+}

pkgs/top-level/python-packages.nix

@@ -268,19 +268,7 @@ in {
 
   vega = callPackage ../development/python-modules/vega { };
 
-  acme = buildPythonPackage rec {
-    inherit (pkgs.certbot) src version;
-
-    name = "acme-${version}";
-
-    propagatedBuildInputs = with self; [
-      cryptography pyasn1 pyopenssl pyRFC3339 pytz requests six werkzeug mock
-      ndg-httpsclient
-    ];
-
-    buildInputs = with self; [ nose ];
-    postUnpack = "sourceRoot=\${sourceRoot}/acme";
-  };
+  acme = callPackage ../development/python-modules/acme { };
 
   acme-tiny = buildPythonPackage rec {
     name = "acme-tiny-${version}";