app.router deprecated message even after app.use(app.router) removed - node.js

Question

I have an app that I'm trying to make into an API with lambda and claudia. I'm getting 'Error: 'app.router' is deprecated' even after I remove the line app.use(app.router) which is what the docs say: https://github.com/expressjs/express/wiki/Migrating-from-3.x-to-4.x
here is my server.js code: (i removed any adding of paths and it still gives me that error)
const express = require('express');
const path = require('path');
const favicon = require('serve-favicon');
const logger = require('morgan');
const cookieParser = require('cookie-parser');
const bodyParser = require('body-parser');
const app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'hbs');
app.use(favicon(path.join(__dirname, 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static('assets'));
app.use(enableCors);
// catch 404 and forward to error handler
app.use((req, res, next) => {
const 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((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((err, req, res, next) => {
res.status(err.status || 500);
res.render('error', {
message: err.message,
error: {}
});
});
function enableCors(req, res, next) {
res.header('Access-Control-Allow-Origin', '*');
res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept');
next();
}
module.exports = app;
Could this have something to do with caching? Are there any other methods that I need to update in order to satisfy the 'app.router deprecated' call?