updated to match

backend/lib/models/authentication.js

     static get joiSchema() {
         return Joi.object({
             user_email: Joi.string().required(),
+            created_at: Joi.date().required(),
             token: Joi.string().required()
         })
     }

backend/lib/schemas/authentication.js

 const userAuth = Joi.object({
     user_email: Joi.string(),
     created_at: Joi.date(),
-    updated_at: Joi.date(),
     token: Joi.string()
 }).label('user_auth')