refactor: migration Negroni from codegangsta to urfave

vendor/github.com/urfave/negroni/doc.go

@@ -0,0 +1,25 @@
+// Package negroni is an idiomatic approach to web middleware in Go. It is tiny, non-intrusive, and encourages use of net/http Handlers.
+//
+// If you like the idea of Martini, but you think it contains too much magic, then Negroni is a great fit.
+//
+// For a full guide visit http://github.com/urfave/negroni
+//
+//  package main
+//
+//  import (
+//    "github.com/urfave/negroni"
+//    "net/http"
+//    "fmt"
+//  )
+//
+//  func main() {
+//    mux := http.NewServeMux()
+//    mux.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
+//      fmt.Fprintf(w, "Welcome to the home page!")
+//    })
+//
+//    n := negroni.Classic()
+//    n.UseHandler(mux)
+//    n.Run(":3000")
+//  }
+package negroni