Add Syntax job for os-ansible-deployment

This patch inserts a syntax check (using ansible-playbook
--syntax-check) before the existing lint job. The lint tool throws
exceptions on invalid playbooks so it makes sense to check for syntax
first.

Exclusions from syntax checking:
 * Playbooks that use vars_prompt due to ansible bug
   https://github.com/ansible/ansible/issues/9607

 * os-service-config-update.yml as it attempts to include a role based on
   a variable that isn't available at syntax check time.

Change-Id: I724bf0b8b3dd1e4bf3b1bd5a24b2c62eee912efb
Merge "Add Syntax job for os-ansible-deployment"