Use package module to install distro packages

Consolidate distro package install tasks into a
single task using the package module and pass
the package list into the name instead of using
a with_items loop.

The minimum Ansible version is raised to 2.2 due to a
known bug [1] in Ansible's apt module which does not
update the cache properly if the cache update and the
install are combined in a single task.

[1] ansible/ansible-modules-core#1497

Also:
- add license boilerplate to meta file

Change-Id: I0d98c4b7bfbc8fe1bd7c8d1e2b83415f1842fd58
(cherry picked from commit 752a834)

meta/main.yml

@@ -1,10 +1,24 @@
 ---
+# Copyright 2017, 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.
+
 galaxy_info:
   author: Steve Lewis
   description: An Ansible Galaxy Role for Deploying OpenStack Gnocchi
   company:
   license: Apache
-  min_ansible_version: 2.0
+  min_ansible_version: 2.2
   platforms:
   - name: Ubuntu
     versions:

tasks/gnocchi_install.yml

@@ -13,15 +13,16 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-- include: gnocchi_install_apt.yml
-  static: no
-  when:
-    - ansible_pkg_mgr == 'apt'
-
-- include: gnocchi_install_yum.yml
-  static: no
-  when:
-    - ansible_pkg_mgr == 'yum'
+- name: Install distro packages
+  package:
+    name: "{{ gnocchi_distro_packages }}"
+    state: "{{ gnocchi_package_state }}"
+    update_cache: "{{ (ansible_pkg_mgr == 'apt') | ternary('yes', omit) }}"
+    cache_valid_time: "{{ (ansible_pkg_mgr == 'apt') | ternary(cache_timeout, omit) }}"
+  register: install_packages
+  until: install_packages|success
+  retries: 5
+  delay: 2
 
 - name: Create developer mode constraint file
   copy: