Optimise apt cache update task

The update of the apt cache and the package installation
can all be handled in a single task by providing the
package action plugin with the right parameters. This
removes an extra task to optimise execution.

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] https://github.com/ansible/ansible-modules-core/issues/1497

Change-Id: I281016d1e836705afec1579192647ed7c6a7e7cd

meta/main.yml

@@ -15,10 +15,10 @@
 
 galaxy_info:
   author: rcbops
-  description: Installation and setup of HAProxy
+  description: Installation and setup of pip
   company: Rackspace
   license: Apache2
-  min_ansible_version: 1.6.6
+  min_ansible_version: 2.2
   platforms:
     - name: Ubuntu
       versions:

tasks/pre_install_apt.yml

@@ -13,16 +13,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-- name: Ensure apt cache is up to date
-  apt:
-    update_cache: yes
-    cache_valid_time: "{{ cache_timeout }}"
-
 # Under Ubuntu, this will only add the key
 - name: Install UCA repository key
   apt:
     name: "{{ pip_install_external_repo_key_package }}"
     state: "{{ pip_install_external_repo_key_package_state | default('present') }}"
+    update_cache: yes
+    cache_valid_time: "{{ cache_timeout }}"
   when:
     - user_external_repo_key is not defined
   tags: