Update core to actually handle sessions correctly
Update core to actually handle sessions correctly

Summary: Allows for core to be different but share the rest

Test Plan: None

Reviewers: #everyone, jslemboski

Reviewed By: #everyone, jslemboski

Subscribers: mclawson

Differential Revision: https://dev.blendtec.com/D1564

Blendtec/opsworks-cookbooks,Blendtec/opsworks-cookbooks