add option nginx.conf worker_limit_nofiles (#1)

* add worker_limit_nofiles option

* keep up with tree atrr. structure

* Update static.sls
diff --git a/tests/pillar/static.sls b/tests/pillar/static.sls
index 4e565f2..1a40205 100644
--- a/tests/pillar/static.sls
+++ b/tests/pillar/static.sls
@@ -8,6 +8,9 @@
     bind:
       address: 127.0.0.1
       protocol: tcp
+    worker:
+      limit:
+        nofile: 30000
     site:
       nginx_static_site01:
         enabled: true