gnu: Add python-cfgraph.

* gnu/packages/rdf.scm (python-cfgraph): New variable.

gnu/packages/rdf.scm

@@ -393,3 +393,23 @@ powerful language for representing information.")
     (description "This package provides an rdflib extension adding JSON-LD
 parser and serializer.")
     (license license:bsd-3)))
+
+(define-public python-cfgraph
+  (package
+    (name "python-cfgraph")
+    (version "0.2.1")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (pypi-uri "CFGraph" version))
+        (sha256
+         (base32
+          "0x7yz0lvqb6mkhl5fbml27sppmscgpf8v2ism9jzzf0h982ffzxm"))))
+    (build-system python-build-system)
+    (propagated-inputs
+     `(("python-rdflib" ,python-rdflib)))
+    (home-page "https://github.com/hsolbrig/CFGraph")
+    (synopsis "RDF Collections flattener for rdflib")
+    (description
+     "This package contains RDF Collections flattener for @code{rdflib}.")
+    (license license:asl2.0)))