fix golint issues in rest (#529)

rest/types.go

@@ -3,14 +3,17 @@ package rest
 import "net/http"
 
 type (
+	// Middleware defines the middleware method.
 	Middleware func(next http.HandlerFunc) http.HandlerFunc
 
+	// A Route is a http route.
 	Route struct {
 		Method  string
 		Path    string
 		Handler http.HandlerFunc
 	}
 
+	// RouteOption defines the method to customize a featured route.
 	RouteOption func(r *featuredRoutes)
 
 	jwtSetting struct {