gnu: Add python-voluptuous.

* gnu/packages/python-xyz.scm (python-voluptuous): New variable.

gnu/packages/python-xyz.scm

@@ -19660,3 +19660,24 @@ workspace...")
 dependencies.  It implements the @uref{http://opensoundcontrol.org/spec-1_0,
 Open Sound Control 1.0} specification.")
     (license license:unlicense)))
+
+(define-public python-voluptuous
+  (package
+    (name "python-voluptuous")
+    (version "0.11.7")
+    (source
+      (origin
+        (method url-fetch)
+        (uri (pypi-uri "voluptuous" version))
+        (sha256
+          (base32
+            "0mplkcpb5d8wjf8vk195fys4y6a3wbibiyf708imw33lphfk9g1a"))))
+    (build-system python-build-system)
+    (native-inputs
+     `(("python-nose" ,python-nose)))
+    (home-page "https://github.com/alecthomas/voluptuous")
+    (synopsis "Python data validation library")
+    (description
+     "Voluptuous is a Python data validation library.  It is primarily
+intended for validating data coming into Python as JSON, YAML, etc.")
+    (license license:bsd-3)))