CORD-536 updated to support the setting of repo via vars

Change-Id: I84988b634967d8be2e5a9f3a79352be5efa9c0c0
diff --git a/roles/ansible/tasks/main.yml b/roles/ansible/tasks/main.yml
index 2cf2f07..faffdd1 100644
--- a/roles/ansible/tasks/main.yml
+++ b/roles/ansible/tasks/main.yml
@@ -1,7 +1,7 @@
 - name: Ansible Repository
   become: yes
   apt_repository:
-    repo="ppa:ansible/ansible"
+    repo: "{{ ansible_apt_repo | default('ppa:ansible/ansible') }}"
 
 - name: Ensure Ansible
   become: yes