pygraphviz: init at 1.3

changes by @globin:
1.2 -> 1.3
correct license information

Signed-off-by: Robin Gloster <[e-mail]>

pkgs/top-level/python-packages.nix

···
     };
   };
 
+  pygraphviz = buildPythonPackage rec {
+    version = "1.3";
+    name = "pygraphviz-${version}";
+
+    src = pkgs.fetchurl {
+      url = "https://github.com/pygraphviz/pygraphviz/archive/${name}.tar.gz";
+      sha256 = "1fhn123hy4qj0zmmmbx0q0r4hwikay13yirsp74niiw5d52y7ib8";
+    };
+
+    propagatedBuildInputs = [ pkgs.graphviz pkgs.pkgconfig ];
+
+    meta = {
+      description = "Python interface to Graphviz graph drawing package";
+      homepage = https://github.com/pygraphviz/pygraphviz;
+      license = licenses.bsd3;
+      maintainers = with maintainers; [ matthiasbeyer ];
+    };
+  };
+
   pymysql = buildPythonPackage rec {
     name = "pymysql-${version}";
     version = "0.6.6";