add view engine

backend/express.js

@@ -40,6 +40,8 @@ alexaApp.express({
 
 // from here on you can setup any other express routes or middlewares as normal
 
+app.set("view engine", "ejs");
+
 alexaApp.launch(function(request, response) {
   const skill = db.collection('skill_list').findOne({_id: ObjectID(skillDbID)}, (err,result)=>{
     if (err){
@@ -172,4 +174,4 @@ MongoClient.connect (config.dbURL).then (database => {
   });
 }).catch(e=>{
   console.log("error : " + e);
-});
+});