Use phusion/passenger as base image
There's a better way to tag an image
Add dockerizer command
Work in progress
Fix bugs
Fix another bug
Patch Heroku buildpacks to increase their download timeouts.

The Heroku buildpacks have a too low timeout for downloading
large (> 100 MB) binary files, causing them to fail on dev
machines where the Internet connection isn't so fast.
We patch the timeouts to 10 minutes.