roles/certbot: add alternate fqdns variable

roles/certbot/defaults/main.yaml

@@ -1,3 +1,4 @@
 ---
 webserver_name: 'nginx'
+certbot_site_alternate_fqdns: []
 ...

roles/certbot/tasks/main.yaml

@@ -26,6 +26,9 @@
         --email {{ letsencrypt_email }}
         --preferred-challenges http
         -d {{ certbot_site_fqdn }}
+    {% for fqdn in certbot_site_alternate_fqdns %}
+        -d {{ fqdn }}
+    {% endfor %}
         -n
   args:
     creates: '/etc/letsencrypt/live/{{ certbot_site_fqdn }}/cert.pem'