Revert "fix to not being able to touch file in /tmp"

This reverts commit 9eb1af7664bac16fdf60e3e9e9e1540e03756601.
Revert "New path to buildpack URL"

This reverts commit 25af231d66d8e0599e80d7b3e14bd8fbac8525b0.
Revert "Update unicorn config to listen on NGINX socket."

This reverts commit b67582d1912cf40544be976e4e98b1b0b5d88771.
Revert "Add multi-buildpack"

This reverts commit 9df0e9b47a5f6fc8001d97817ef3a6b2836b3e15.