[CORD-2874]
Fix deprecation warnings raised by Ansible 2.5

Change-Id: Icb607d267af2771b046b46399ce5f0d182f629ab
diff --git a/roles/ansible-install/tasks/main.yml b/roles/ansible-install/tasks/main.yml
index fc66b18..40831ed 100644
--- a/roles/ansible-install/tasks/main.yml
+++ b/roles/ansible-install/tasks/main.yml
@@ -1,4 +1,4 @@
-
+---
 # Copyright 2017-present Open Networking Foundation
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -13,8 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-
----
 # file: ansible-install/tasks/main.yml
 
 - name:  Install prerequisites for using PPA repos
@@ -33,7 +31,7 @@
   with_items:
     - "{{ ansible_apt_repo | default('ppa:ansible/ansible') }}"
   register: result
-  until: result | success
+  until: result is success
   retries: 3
   delay: 10
 
@@ -44,4 +42,4 @@
     update_cache: yes
     cache_valid_time: 3600
   tags:
-    - skip_ansible_lint # ansible-lint complains about latest, need this as distro provided 1.5.x version may be used if already installed.
\ No newline at end of file
+    - skip_ansible_lint # ansible-lint complains about latest, need this as distro provided 1.5.x version may be used if already installed.