为什么在Heroku上收到此错误“ at =错误代码= H10 desc =“应用程序崩溃””？

I have deployed my application written with Go to Heroku. As soon as I open app it gives me error. I check logs it shows this error. PS. I am listening by calling http.ListenAndServe(":"+os.Getenv("PORT"), nil). I have set PORT environment variable to :80.