NGINX forwarding on DO: mup issues - meteor

Question

There have been many posts about NGINX and Meteor.js (using mup). However, none of them seemed to solve for my case. I can't get the NGINX vhost to forward it correctly to where my app lives on my DigitalOcean droplet.
Here's my mup.json:
{
"servers": [
{
"host": <IP-address>,
"username": "root",
"password": <root pwd>
}
],
"setupMongo": true,
"setupNode": true,
"nodeVersion": "0.10.36",
"setupPhantom": true,
"enableUploadProgressBar": true,
"appName": myapp,
"app": ".",
"env": {
"ROOT_URL": "http://localhost",
"PORT" : 3000,
"METEOR_ENV": "development"
},
"deployCheckWaitTime": 15
}
Then, on my droplet, I have deleted /etc/nginx/sites-enabled/default and created: /etc/nginx/sites-enabled/myapp.com.conf together with a sym-link in sites-available, that looks like:
server {
listen *:80;
server_name myapp.com;
access_log /var/log/nginx/app.dev.access.log;
error_log /var/log/nginx/app.dev.error.log;
location / {
proxy_pass http://localhost:3000;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header X-Forwarded-For $remote_addr;
}
}
After restarting NGINX, when I locally do mup deploy it cannot deploy with the message Failed to connect to localhost port 3000: Connection refused i.e. the app cannot be connected to on the droplet.
I've been banging my head against the wall for some days, any ideas what can be the issue?