Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch

[nelsonic]

2017-10-03T09:06:19.988494+00:00 app[web.1]: > node example/github_server.js
2017-10-03T09:06:19.988495+00:00 app[web.1]: 
2017-10-03T09:06:20.131086+00:00 app[web.1]: �[1m�[43m�[30m WARNING: �[22m�[42m�[30m env2 was required to load an .env file: �[46m�[30m /app/.env �[1m�[43m�[30m NOT FOUND! �[22m�[42m�[30m Please see: http://git.io/vG3UZ�[49m�[39m�[22m
2017-10-03T09:06:21.176535+00:00 app[web.1]: Now Visit: http://localhost:20094
2017-10-03T09:07:17.051002+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch
2017-10-03T09:07:17.051002+00:00 heroku[web.1]: Stopping process with SIGKILL
2017-10-03T09:07:17.209186+00:00 heroku[web.1]: Process exited with status 137
2017-10-03T09:07:17.217016+00:00 heroku[web.1]: State changed from starting to crashed