I've managed to install Magento 2 on heroku - I had to say it took me couple of days to get to this point. However, once I logged to the admin area and trying to create a simple product, it does not show up the product form at all. It works fine on the local enviroment but not on heroku staging enviroment.
I'm actually getting this error message in the heroku server log
[Mon Aug 24 21:36:26.702790 2015] [access_compat:error] [pid 122:tid 140281181558528] [client 10.79.141.18:35276] AH01797: client denied by server configuration: /app/app/etc/config.php
(btw Heroku name the home folder of the application is app so the above link to config.php file is fine )
The weird thing is that no 'config.php' under /app/etc/ folder.
Magento was installed via web wizard on the staging site so I guess the file must be created by itself.
i am planning on giving this a try myself this week. I'll post any updates on it that might help....with that being said, Heroku is a read only environment...you would not be able to create a config.php file via a wizard ON Heroku. Post install you woud have to create it locally and push it up to Heroku manually.