Retire devstack-plugin-pika project

This plugin was used by the oslo.messaging project to test the
development of an alternative RabbitMQ message driver based on
the Pika library (instead of the default Kombu driver).

Development of this driver was dropped in Queens and is not
supported.

Depends-On: https://review.opendev.org/745342
Change-Id: I74b80797edc3b6c93f19498100ab5a0c2a0e18ac

.zuul.yaml

@@ -1,7 +0,0 @@
-- project:
-    check:
-      jobs:
-        - openstack-tox-bashate
-    gate:
-      jobs:
-        - openstack-tox-bashate

README.rst

@@ -0,0 +1,6 @@
+This project is no longer maintained.
+
+The contents of this repository are still available in the Git
+source code management system.  To see the contents of this
+repository before it reached its end of life, please check out the
+previous commit with "git checkout HEAD^1".

devstack/plugin.sh

@@ -1,38 +0,0 @@
-#!/bin/bash
-#
-# Copyright 2015 Hewlett-Packard Development Company, L.P.
-#
-# Licensed under the Apache License, Version 2.0 (the "License"); you may
-# not use this file except in compliance with the License. You may obtain
-# a copy of the License at
-#
-#    http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-# License for the specific language governing permissions and limitations
-# under the License.
-
-function get_transport_url {
-    local virtual_host=$1
-    echo "pika://$RABBIT_USERID:$RABBIT_PASSWORD@$RABBIT_HOST:5672/$virtual_host"
-}
-
-function get_notification_url {
-    local virtual_host=$1
-    echo "pika://$RABBIT_USERID:$RABBIT_PASSWORD@$RABBIT_HOST:5672/$virtual_host"
-}
-
-# Note: no need to override default 'rpc_backend_add_vhost' since the
-# backend is also rabbitmq
-
-function iniset_rpc_backend {
-    local package=$1
-    local file=$2
-    local section=${3:-DEFAULT}
-    local virtual_host=$4
-
-    iniset $file $section transport_url $(get_transport_url "$virtual_host")
-    iniset $file oslo_messaging_notifications transport_url $(get_notification_url "$virtual_host")
-}

tox.ini

@@ -1,26 +0,0 @@
-[tox]
-minversion = 3.1.1
-skipsdist = True
-envlist = bashate
-ignore_basepython_conflict = true
-
-[testenv]
-basepython = python3
-usedevelop = False
-
-[testenv:bashate]
-deps = bashate
-whitelist_externals = bash
-commands = bash -c "find {toxinidir}          \
-         -not \( -type d -name .?\* -prune \) \
-         -not \( -type d -name doc -prune \)  \
-         -type f                              \
-         -not -name \*~                       \
-         -not -name \*.md                     \
-         \(                                   \
-          -name \*.sh -or                     \
-          -name \*rc -or                      \
-          -name functions\* -or               \
-          -wholename \*/lib/\*                \
-         \)                                   \
-         -print0 | xargs -0 bashate -v"