Small stand-alone URL-echoing server

Program.cs

using Microsoft.Owin;
using Microsoft.Owin.Hosting;
using Owin;
using System;
using System.Net.Http;

namespace SelfHost
{
    public class Program
    {
        public void Main(string[] args)
        {
            var baseAddress = "http://localhost:9000/";
            using (WebApp.Start<Startup>(url: baseAddress))
            {
                Console.WriteLine("Press a key to stop the server...");
                Console.ReadKey(true);
            }
        }
    }
    public class Startup
    {
        public void Configuration(IAppBuilder appBuilder)
        {
            appBuilder.Run(context =>
            {
                return context.Response.WriteAsync(context.Request.Path.Value);
            });
        }
    }
}

project.json

{
    "version": "1.0.0-*",
    "dependencies": {
        "Microsoft.AspNet.WebApi.OwinSelfHost": "5.2.3",
        "Microsoft.AspNet.Mvc": "5.2.3"
    },
    "commands": {
        "run": "run"
    },
    "frameworks": {
        "aspnet50": {
            "dependencies": {
                "System.Console": "4.0.0-beta-22523"
            }
        }
    },
    "compilationOptions": {
        "languageVersion": "csharp6"
    }
}