gnu: Remove duplicate python-prometheus-client.

* gnu/packages/monitoring.scm (python-prometheus-client): Update to 0.7.1.
* gnu/packages/python-xyz.scm (python-prometheus-client): Remove
variable.
* gnu/packages/monitoring.scm: Import (gnu packages monitoring).

gnu/packages/matrix.scm

@@ -20,6 +20,7 @@ (define-module (gnu packages matrix)
   #:use-module ((guix licenses) #:prefix license:)
   #:use-module (gnu packages check)
   #:use-module (gnu packages databases)
+  #:use-module (gnu packages monitoring)
   #:use-module (gnu packages python-crypto)
   #:use-module (gnu packages python-web)
   #:use-module (gnu packages python-xyz)

gnu/packages/monitoring.scm

@@ -5,6 +5,7 @@
 ;;; Copyright © 2018 Tobias Geerinckx-Rice <me@tobias.gr>
 ;;; Copyright © 2018 Gábor Boskovits <boskovits@gmail.com>
 ;;; Copyright © 2018, 2019 Oleg Pykhalov <go.wigust@gmail.com>
+;;; Copyright © 2020 Alex ter Weele <alex.ter.weele@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -371,14 +372,13 @@ (define-public python2-graphite-web
 (define-public python-prometheus-client
   (package
     (name "python-prometheus-client")
-    (version "0.5.0")
+    (version "0.7.1")
     (source
      (origin
        (method url-fetch)
        (uri (pypi-uri "prometheus_client" version))
        (sha256
-        (base32
-         "0g7rpv1pq2lab1nfqdx98z9d3bqwc400alg1j4ynrpjkrbsizhg8"))))
+        (base32 "1ni2yv4ixwz32nz39ckia76lvggi7m19y5f702w5qczbnfi29kbi"))))
     (build-system python-build-system)
     (arguments
      '(;; No included tests.

gnu/packages/python-xyz.scm

@@ -19236,28 +19236,6 @@ (define-public python-pymacaroons
 enforcement of that policy.")
     (license license:expat)))
 
-(define-public python-prometheus-client
-  (package
-    (name "python-prometheus-client")
-    (version "0.7.1")
-    (source
-     (origin
-       (method url-fetch)
-       (uri (pypi-uri "prometheus_client" version))
-       (sha256
-        (base32 "1ni2yv4ixwz32nz39ckia76lvggi7m19y5f702w5qczbnfi29kbi"))))
-    (build-system python-build-system)
-    (arguments
-     ;; TODO: No tests in the PyPI distribution.
-     `(#:tests? #f))
-    (propagated-inputs
-     `(("python-twisted" ,python-twisted)))
-    (home-page "https://github.com/prometheus/client_python")
-    (synopsis "Prometheus instrumentation library")
-    (description
-     "This is the official Python client for the Prometheus monitoring server.")
-    (license license:asl2.0)))
-
 (define-public python-ldap3
   (package
     (name "python-ldap3")