proxy error { [Error: connect ECONNREFUSED 127.0.0.1:80]

Would like to deploy this boilerplate to heroku but getting the above error. Build is successful and website loads but routing seems broken because navigating pages via the navbar does not update the page. Both master and heroku branch produce the same error. Applied the heroku specific steps including:
1. Remove the `"PORT": 8080` line from the `betterScripts` / `start-prod` section of `package.json`.
2. `heroku config:set --app myapp NODE_ENV=production`
3. `heroku config:set --app myapp NODE_PATH=./src`
4. `heroku config:set --app myapp NPM_CONFIG_PRODUCTION=false`
5. created Procfile in root directory with contents: web: node bin/server.js

Full error from heroku logs --tail
2016-03-02T22:59:55.858547+00:00 heroku[router]: at=info method=GET path="/ws/?EIO=3&transport=polling&t=LCvZoIr" host=myapp.herokuapp.com request_id=65ac0375-dcc2-4d53-9ca5-a1b10b119705 fwd="172.58.41.211" dyno=web.1 connect=1ms service=4ms status=500 bytes=321
2016-03-02T22:59:55.853682+00:00 app[web.1]: proxy error { [Error: connect ECONNREFUSED 127.0.0.1:80]
2016-03-02T22:59:55.853693+00:00 app[web.1]: code: 'ECONNREFUSED',
2016-03-02T22:59:55.853729+00:00 app[web.1]: errno: 'ECONNREFUSED',
2016-03-02T22:59:55.853730+00:00 app[web.1]: syscall: 'connect',
2016-03-02T22:59:55.853731+00:00 app[web.1]: address: '127.0.0.1',
2016-03-02T22:59:55.853732+00:00 app[web.1]: port: 80 }

Demo link for this boilerplate seems to work fine on heroku? Did I miss something?