Remove redundant apt cache update task

There's no reason for this task to be in its own file.
It's not used anywhere but this play. The task also is
not necessary, given that every role does its own updates
when it needs to and the test execution does a cache
update right at the start in order to install the dependent
packages.

All in all, this is a waste of time, so let's just purge it.

Change-Id: I9cc872189b87eb65c4ee7623d4141be41d207f7a

common-tasks/test-force-package-cache-update.yml

@@ -1,25 +0,0 @@
----
-# Copyright 2016, Rackspace US, Inc.
-#
-# 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.
-
-- name: First ensure apt cache is always refreshed
-  apt:
-    update_cache: true
-  register: _update
-  retries: 5
-  delay: 2
-  until: _update  is succeeded
-  changed_when: false
-  when:
-    - ansible_pkg_mgr == 'apt'

test-install-openstack-hosts.yml

@@ -23,8 +23,6 @@
   become: yes
   gather_facts: true
   any_errors_fatal: true
-  pre_tasks:
-    - include: "common-tasks/test-force-package-cache-update.yml"
   roles:
     - role: "openstack_hosts"
   vars_files: