Issues with Heroku deploy

Im having an weird issue, or maybe I'm missing something so could you please help!

The issue is that I have deployed my database on mLab and configured my app.js so it can run it:

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var api = require('./routes/api');

var routes = require('./routes/index');
var users = require('./routes/users');
var session = require('express-session');

var app = express();

app.use('/api', api);

var mongoose = require('mongoose');
mongoose.connect('mongodb://<user>:<pass>@ds019624.mlab.com:19624/heroku_b036xcp8');


var db = mongoose.connecetion;

app.use(cookieParser());
app.use(session({ secret: 'sesija', cookie: { maxAge: 60000 }, resave: true, saveUninitialized: true }));

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');


// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

app.use(express.static(path.join(__dirname, 'public')));


app.use('/', routes);
app.use('/users', users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});

as you can see there is a line which says app.use('/api', api); and this is my API which is in my routes folder. the current Folder structures is something like this:

-- models

-- views

-- routes

----- api.js

-- app.js

the api.js is in the routes folder.

When i do localhost/api/something i get the result of the API however on heroku I get a timeout error, is there something wrong in the code or in the folderstructure?

EDIT: api.js

var express = require('express');
var router = express.Router();
var mongoose = require('mongoose');
var Page= require('../models/page.js');
var adminUser= require('../models/admin-users.js');
var bodyParser = require('body-parser').json();
var bcrypt = require('bcrypt-nodejs');



/* User Routes. */

router.get('/admin', function(req, res) {
  res.send('Welcome to the API zone');
});

router.get('/pages', function(request, response) {

        return Page.find(function(err, pages) {
            if (!err) {
                return response.send(pages);
            } else {
                return response.send(500, err);
            }
        });
    });

router.post('/pages/add',bodyParser, function(request, response) {

    var page = new Page({
        title: request.body.title,
        url: request.body.url,
        content: request.body.content,
        menuIndex: request.body.menuIndex,
        date: new Date(Date.now())
    });  

    page.save(function(err) {
        if (!err) {
            return response.send(200, page);
        } else {
            return response.send(500,err);
        }
    });
});

router.post('/pages/update',bodyParser, function(request, response) {
    var id = request.body._id;
    var newid = mongoose.Types.ObjectId();         

    Page.update({
        _id: id
    }, {
        $set: {
            title: request.body.title,
            url: request.body.url,
            content: request.body.content,
            menuIndex: request.body.menuIndex,
            date: new Date(Date.now())
        }
    }).exec();

    response.send("Page updated");
});

router.get('/pages/delete/:id', bodyParser, function(request, response) {
    var id = request.params.id;

    Page.remove({
        _id: id
    }, function(err) {
        return console.log(err);
    });
    return response.send('Page id- ' + id + ' has been deleted');
});


// -----
router.get('/pages/admin-details/:id', bodyParser, function(request, response) {
    var id = request.params.id;
    Page.findOne({
        _id: id
    }, function(err, page) {
        if (err)
            return console.log(err);
        return response.send(page);
    });
});

router.get('/pages/details/:url', function(request, response) {
    var url = request.params.url;
    Page.findOne({
        url: url
    }, function(err, page) {
        if (err)
            return console.log(err);
        return response.send(page);
    });
});


//Admin panel login

router.post('/add-user', bodyParser, function(request, response) {
    var salt, hash, password;
    password = request.body.password;
    salt = bcrypt.genSaltSync(10);
    hash = bcrypt.hashSync(password, salt);

    var AdminUser = new adminUser({
        username: request.body.username,
        password: hash
    });
    AdminUser.save(function(err) {
        if (!err) {
            return response.send('Admin User successfully created');

        } else {
            return response.send(err);
        }
    });
});

router.post('/login', bodyParser ,function(request, response) {
    console.log("this is login api");
  var username = request.body.username;
  var password = request.body.password;


  adminUser.findOne({
    username: username
  }, function(err, data) {
    if (err | data === null) {
      return response.send(401, "User Doesn't exist");
    } else {
      var usr = data;

      if (username == usr.username && bcrypt.compareSync(password, usr.password)) {

        // request.session.regenerate(function() {
        //   request.session.user = username;
         return response.send(username);

        //});
      } else {
        return response.send(401, "Bad Username or Password");
      }
    }
  });
});

router.get('/logout', function(request, response) {
    request.session.destroy(function() {
        return response.send(401, 'User logged out');

    });
});

function sessionCheck(request,response,next){
//check cookie 
    if(request.session.user) next();
        else response.send(401,'authorization failed');
}

module.exports = router;

Error on Heroku:

2016-06-26T18:17:07.046803+00:00 heroku[router]: at=error code=H12 desc="Request timeout" method=GET path="/api/pages" host=app.herokuapp.com request_id=f314665a-9378-437a-a648-c388391fd4c1 fwd="109.163.155.179" dyno=web.1 connect=0ms service=30001ms status=503 bytes=0