Fix role gate tests for Ansible 2.3

Add 'become' and root 'user' options to the playbook instead of using
'ansible_become' through an inventory variable.

Change-Id: I4d94dec6ad68159248007f6845c9e3e09c233bf1

tests/inventory

@@ -1,5 +1,5 @@
 [all]
-localhost ansible_become=True
+localhost
 service1 ansible_host=10.100.100.2 ansible_become=True ansible_user=root
 openstack1 ansible_host=10.100.100.3 ansible_become=True ansible_user=root
 

tests/test-install-cloudkitty.yml

@@ -16,6 +16,7 @@
 - name: Playbook for role testing
   hosts: cloudkitty_all
   user: root
+  become: true
   gather_facts: true
   pre_tasks:
     - name: Ensure Rabbitmq vhost
@@ -37,4 +38,3 @@
     - role: "os_cloudkitty"
   vars_files:
     - common/test-vars.yml
-    - test-vars.yml