change port

import (

	"fmt"

	"log"

	"net/http"

)

func main() {

	http.HandleFunc("/", hello)

    fmt.Println("listening...")

    err := http.ListenAndServe(":5000", nil)

	err := http.ListenAndServe(":"+os.Getenv("PORT"), nil)

	if err != nil {

      panic(err)

		log.Fatal("ListenAndServe:", err)

	}

}