heroku/heroku-buildpack-python — pull request #172 by mansam (2014-09-26 14:39:42+00:00)
Title: Install libffi for bcrypt as well

The `bcrypt` library also needs `libffi`, but that requirement isn't currently detected by the buildpack unless you explicitly add `cffi` to your `requirements.txt` file. This change allows the buildpack to automatically detect the requirement.