create kestrel server for serving static files

util/Server/Program.cs

@@ -0,0 +1,27 @@
+using Microsoft.AspNetCore.Hosting;
+
+namespace Server
+{
+    public class Program
+    {
+        public static void Main(string[] args)
+        {
+            var builder = new WebHostBuilder()
+                .UseKestrel()
+                .UseStartup<Startup>();
+
+            if(args.Length > 0)
+            {
+                builder.UseContentRoot(args[0]);
+            }
+
+            if(args.Length > 1)
+            {
+                builder.UseWebRoot(args[1]);
+            }
+
+            var host = builder.Build();
+            host.Run();
+        }
+    }
+}