Address Ansible bare variable usage

When executing the role with Ansible 2.1, the following
deprecation warning is issued in the output for some tasks.

[DEPRECATION WARNING]: Using bare variables is deprecated.

This patch addresses the tasks to fix the behaviour appropriately.

Change-Id: Ida87ec8609c870010cb92a45d78d1a506252d5f3

handlers/main.yml

@@ -28,4 +28,4 @@
     name: "{{ item }}"
     state: "restarted"
     pattern: "{{ item }}"
-  with_items: sahara_service_names
+  with_items: "{{ sahara_service_names }}"

tasks/sahara_install.yml

@@ -71,7 +71,7 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  with_items: sahara_required_pip_packages
+  with_items: "{{ sahara_required_pip_packages }}"
   tags:
     - sahara-install
     - sahara-pip-packages
@@ -189,7 +189,7 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  with_items: sahara_pip_packages
+  with_items: "{{ sahara_pip_packages }}"
   when:
     - sahara_venv_enabled | bool
     - sahara_get_venv | failed or sahara_developer_mode | bool
@@ -208,7 +208,7 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  with_items: sahara_pip_packages
+  with_items: "{{ sahara_pip_packages }}"
   when:
     - not sahara_venv_enabled | bool
     - not sahara_developer_mode | bool

tasks/sahara_install_apt.yml

@@ -32,4 +32,4 @@
   until: install_packages|success
   retries: 5
   delay: 2
-  with_items: sahara_apt_packages
+  with_items: "{{ sahara_apt_packages }}"