set heroku_wsgi in Procfile

Procfile

@@ -1,2 +1,2 @@
 release: yes "yes" | python manage.py migrate
-web: uwsgi --http :$PORT --module bakerydemo.wsgi --master --offload-threads 1
+web: uwsgi --http :$PORT --module bakerydemo.heroku_wsgi --master --offload-threads 1