add cache-control header

nginx/default.conf

@@ -25,6 +25,9 @@ server {
         # Set our custom CORS
         #add_header 'Access-Control-Allow-Origin' $allow_origin;
 
+        # Set Cache-Control
+        add_header Cache-Control "max-age=0, stale-while-revalidate=604800";
+
         # If you need to see nginx cache status. Uncomment line below.
         add_header X-Cache-Status $upstream_cache_status;
     }