added device_inventory
Merge branch 'questionnaires_v2' of github.com:MIT-Model-Open-Data-and-Identity-System/SensibleData-Service into questionnaires_v2

* 'questionnaires_v2' of github.com:MIT-Model-Open-Data-and-Identity-System/SensibleData-Service:
  fixed issue with database class when not using a replica set.