Workaround if bluepill does not support conf_dir

Public cookbook bluepill 2.3.1 http://community.opscode.com/cookbooks/bluepill it does not appear to support conf_dir, so we needed this workaround in order to use the datomic cookbook https://github.com/RallySoftware-cookbooks/datomic.

Fixes https://github.com/RallySoftware-cookbooks/datomic/issues/4