add Chance.prototype.unique for a unique array
Breaking up states in default (US/DC), territores, and armed forces.
Merge pull request #65 from alexdiliberto/develop

Added Chance ssn() feature. Also fixed outstanding JSHint errors.
Added Chance ssn() feature. Also fixed outstanding JSHint errors.
Merge branch 'alexdiliberto-states' into develop
Added Chance ssn() feature. Also fixed outstanding JSHint errors.
Breaking up states in default (US/DC), territores, and armed forces.
Merge branch 'akre54-unique-array' into develop