Django heroku deploy results in site cant be reached error

[Dave N]

My full django deploy issue can be found here: http://stackoverflow.com/questions/37714253/django-deploy-on-heroku-gives-site-cant-be-reached-response

In summary, my app works locally with runserver, and also works perfectly when I use heroku local on 0.0.0.0:5000. When I introduce gunicorn my app gives a blank page with "This site can’t be reached, localhost took too long to respond”. Looking through heroku logs, I get no error code, just evidence of 301 redirects. Same result on sitename.herokuapp.com

Any idea how I can get my app to serve correctly in the wild?