use submodule

vendor/github.com/gorilla/handlers/handlers_go18.go

@@ -1,21 +0,0 @@
-// +build go1.8
-
-package handlers
-
-import (
-	"fmt"
-	"net/http"
-)
-
-type loggingResponseWriter interface {
-	commonLoggingResponseWriter
-	http.Pusher
-}
-
-func (l *responseLogger) Push(target string, opts *http.PushOptions) error {
-	p, ok := l.w.(http.Pusher)
-	if !ok {
-		return fmt.Errorf("responseLogger does not implement http.Pusher")
-	}
-	return p.Push(target, opts)
-}