user error message

stubs/api/index.js

@@ -21,10 +21,10 @@ router.post('/lesson/access-code', (req, res) => {
 })
 
 router.get('/lesson/access-code/:accessCode', (req, res) => {
-  res.send(require('../mocks/lessons/access-code/get/success.json'))
+  res.status(400).send(require('../mocks/lessons/access-code/get/error.json'))
 })
 
-router.get('/api/lesson/:lessonId', (req, res) => {
+router.get('/lesson/:lessonId', (req, res) => {
   res.send(require('../mocks/lessons/byid/success.json'))
 })
 

stubs/mocks/lessons/access-code/get/error.json

@@ -0,0 +1 @@
+{ "success": false, "body": { "errorMessage": "Code is expired" } }