use submodule

vendor/github.com/gorilla/mux/context_gorilla.go

@@ -1,26 +0,0 @@
-// +build !go1.7
-
-package mux
-
-import (
-	"net/http"
-
-	"github.com/gorilla/context"
-)
-
-func contextGet(r *http.Request, key interface{}) interface{} {
-	return context.Get(r, key)
-}
-
-func contextSet(r *http.Request, key, val interface{}) *http.Request {
-	if val == nil {
-		return r
-	}
-
-	context.Set(r, key, val)
-	return r
-}
-
-func contextClear(r *http.Request) {
-	context.Clear(r)
-}