[No Ticket] Add get_object to interpret JSON settings

[icereval]

Ticket

N/A

Purpose

Allow JSON objects and arrays to be passed into as environment variable settings, needed for Storage Internationalization project.

Changes

Adds get_object to the base Settings class.

Side effects

None

QA Notes

N/A

Deployment Notes

N/A

[coveralls]

Coverage increased (+0.02%) to 71.276% when pulling c070e6d on icereval:hotfix/settings-get-object into fbe2cca on CenterForOpenScience:master.