Auto-fix yaml rules

In order to reduce divergance with ansible-lint rules, we apply
auto-fixing of violations.

In current patch we replace all kind of truthy variables with
`true` or `false` values to align with recommendations along with
alignment of used quotes.

Change-Id: I3f4375c6218f6a0f92fdb1c33471d2ab827ba4be

.gitignore

@@ -45,6 +45,7 @@ logs/*
 # OS generated files #
 ######################
 ._*
+.ansible
 .tox
 *.egg-info
 .eggs

tasks/main.yml

@@ -24,7 +24,6 @@
   tags:
     - always
 
-
 - name: Including osa.db_setup role
   include_role:
     name: openstack.osa.db_setup
@@ -53,7 +52,7 @@
 - name: Retrieve the constraints URL
   uri:
     url: "{{ rally_upper_constraints_url }}"
-    return_content: yes
+    return_content: true
   register: _u_c_contents_uri
   until: _u_c_contents_uri is success
   retries: 5