Optinally use stage to generate simulated endponts

lib/serve.js

@@ -42,7 +42,10 @@ module.exports = {
     for (let funcConf of funcConfs) {
       for (let httpEvent of funcConf.events) {
         const method = httpEvent.method.toLowerCase();
-        const endpoint = `/${this.options.stage}/${httpEvent.path}`;
+        let endpoint = `/${httpEvent.path}`;
+        if (this.options.stage) {
+          endpoint = `/${this.options.stage}${endpoint}`;
+        }
         const path = endpoint.replace(/\{(.+?)\}/g, ':$1');
         let handler = this._handlerBase(funcConf);
         let optionsHandler = this._optionsHandler;