react-express-mongodb: rename server to backend

The goal here is to keep the same structure than the other examples.
Also, considering that it has a "frontend" folder, the equivalent for
the server should be "backend".

Signed-off-by: Jérémie Drouet <jeremie.drouet@gmail.com>

react-express-mongodb/backend/routes/index.js

@@ -0,0 +1,38 @@
+const express = require('express');
+const serverResponses = require('../utils/helpers/server.responses');
+const messages = require('../config/messages');
+var {Todo} = require('../models/todos/todo.model');
+
+const routes = (app) => {
+    const router = express.Router();
+
+    router.post('/todos', (req,res)=>{
+        var todo = new Todo({
+            text: req.body.text
+        });
+
+        todo.save()
+            .then((result)=>{
+                serverResponses.sendSuccess(res,messages.SUCCESSFUL, result);
+            })
+            .catch((e) => {
+                serverResponses.sendError(res,messages.BAD_REQUEST,e)
+            })
+    });
+
+    router.get('/', (req,res) => {
+        Todo.find({}, {__v:0})
+            .then((todos)=>{
+                serverResponses.sendSuccess(res,messages.SUCCESSFUL, todos);
+
+            })
+            .catch((e) => {
+                serverResponses.sendError(res,messages.BAD_REQUEST,e)
+            })
+    });
+
+    //it's a prefix before api it is useful when you have many modules and you want to
+    //differentiate b/w each module you can use this technique
+    app.use('/api', router);
+};
+module.exports = routes;