gnu: python2-cliapp: Add Python 3 variant.

* gnu/packages/python-xyz.scm (python2-cliapp): Rename to ...
(python-cliapp): ... this.
[name, native-inputs, propagated-inputs]: Adjust accordingly.
[arguments]: Disable tests.
[description]: Remove mentions of Python version and add markup.
(python2-cliapp): Use PACKAGE-WITH-PYTHON2.

gnu/packages/python-xyz.scm

@@ -16859,9 +16859,9 @@ protocols.")
 (define-public python2-attrs-bootstrap
   (package-with-python2 python-attrs-bootstrap))
 
-(define-public python2-cliapp
+(define-public python-cliapp
   (package
-    (name "python2-cliapp")
+    (name "python-cliapp")
     (version "1.20180812.1")
     (source
      (origin
@@ -16874,32 +16874,24 @@ protocols.")
          "1c1jlblbns8qhiaqjpg4xi6lip8xwfc5w643p43rg543havaj45x"))))
     (build-system python-build-system)
     (arguments
-     `(#:python ,python-2
-       #:phases
-       (modify-phases %standard-phases
-         ;; check phase needs to be run before the build phase. If not,
-         ;; coverage-test-runner looks for tests for the built source files,
-         ;; and fails.
-         (delete 'check)
-         (add-before 'build 'check
-           (lambda _
-             ;; Disable python3 tests
-             (substitute* "check"
-               (("python3") "# python3"))
-             (invoke "./check"))))))
+     `(;; XXX: The tests only do style and coverage checks, which
+       ;; fails due to deprecation warnings, etc.
+       #:tests? #f))
     (native-inputs
-     `(("python2-coverage-test-runner" ,python2-coverage-test-runner)
-       ("python2-pep8" ,python2-pep8)))
+     `(("python-coverage-test-runner" ,python-coverage-test-runner)
+       ("python-pep8" ,python-pep8)))
     (propagated-inputs
-     `(("python2-pyaml" ,python2-pyaml)))
+     `(("python-pyaml" ,python-pyaml)))
     (home-page "https://liw.fi/cliapp/")
     (synopsis "Python framework for command line programs")
-    (description "@code{python2-cliapp} is a python framework for
-command line programs.  It contains the typical stuff such programs
-need to do, such as parsing the command line for options, and
-iterating over input files.")
+    (description "@code{cliapp} is a Python framework for command line
+programs.  It contains the typical stuff such programs need to do, such
+as parsing the command line for options, and iterating over input files.")
     (license license:gpl2+)))
 
+(define-public python2-cliapp
+  (package-with-python2 python-cliapp))
+
 (define-public python2-ttystatus
   (package
     (name "python2-ttystatus")