gnu: python-attrs: Update to 17.4.0.

* gnu/packages/python.scm (python-attrs)[version]: Update to 17.4.0.
[native-inputs]: Add python-sphinx and python-coverage.  Reorder inputs.

gnu/packages/python.scm

@@ -10729,19 +10729,22 @@ and bit flag values.")
 (define-public python-attrs
   (package
     (name "python-attrs")
-    (version "17.2.0")
-    (source (origin
-              (method url-fetch)
-              (uri (pypi-uri "attrs" version))
-              (sha256
-               (base32
-                "04gx08ikpk26wnq22f7l42gapcvk8iz1512r927k6sadz6cinkax"))))
+    (version "17.4.0")
+    (source
+     (origin
+       (method url-fetch)
+       (uri (pypi-uri "attrs" version))
+       (sha256
+        (base32
+         "1jafnn1kzd6qhxgprhx6y6ik1r5m2rilx25syzcmq03azp660y8w"))))
     (build-system python-build-system)
     (native-inputs
-     `(("python-pytest" ,python-pytest)
+     `(("python-coverage" ,python-coverage)
        ("python-hypothesis" ,python-hypothesis)
-       ("python-zope-interface" ,python-zope-interface)
-       ("python-six" ,python-six)))
+       ("python-pytest" ,python-pytest)
+       ("python-six" ,python-six)
+       ("python-sphinx" ,python-sphinx)
+       ("python-zope-interface" ,python-zope-interface)))
     (home-page "https://github.com/python-attrs/attrs/")
     (synopsis "Attributes without boilerplate")
     (description "@code{attrs} is a Python package with class decorators that