PHP version: 5.4.12.

Closes #20.
Use relative paths in nginx.conf.
Added tests for nginx.conf.
Updated README as `heroku config:add PATH` is no longer needed.

Closes #22.
Make sed work on both Linux and OSX in newrelic package script.

sed threw a 'bad flag in substitute command: f' when run. Added a -e
flag to fix this.
Nginx version: 1.2.8.

Closes #24.
Nginx version: 1.4.0.

Closes #26.
Nginx version: 1.4.1.

Closes #27.
Merge commit '31b36bc8d5322022945734c3caaeb6602bfcb348' into develop
Changing to new build pack s3 repository