[nginx] Add nginx playbook

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>

plays/nginx.yml

+#!/usr/bin/env ansible-playbook
+---
+- hosts: nginx
+  vars:
+    nginx: '{{ glob_nginx | default({}) | combine(loc_nginx | default({})) }}'
+  roles:
+    - nginx