Heroku Current Version Number in Node.js

herokuRelease.js

var _ = require('lodash'),
    Heroku = require('heroku-client'),
    heroku = new Heroku({ token: process.env.HEROKU_API_KEY });
    
var app = heroku.apps('application-name');
app.releases().list(function(err, releases) {
    var version = _.max(_.pluck(releases, 'version'));
    console.log("APP_VERSION: " + version);
    process.env.APP_VERSION = version;
});