gnu: python-feedparser: Disable the test suite.

The tests were silently skipped with Python 3.4. With Python 3.5, this caused
the build of python-feedparser to fail.

* gnu/packages/python.scm (python-feedparser, python2-feedparser)[arguments]:
Disable the tests.

gnu/packages/web.scm

@@ -3161,6 +3161,8 @@ their web site.")
         (base32
          "00hb4qg2am06g81mygfi1jsbx8830024jm45g6qp9g8fr6am91yf"))))
     (build-system python-build-system)
+    (arguments
+     '(#:tests? #f))
     (home-page
      "https://github.com/kurtmckee/feedparser")
     (synopsis "Parse feeds in Python")