Fix support for custom root in JSON-API adapter
Renamed embed test to have "test" suffix
Fixed reference to association options
Merge pull request #689 from ride/fix-json-api-custom-root

Fix support for custom root in JSON-API adapter
Merge pull request #691 from jacob-s-son/fix-embed-option-for-associations

Fix embed option for associations
Handle correctly null associations

null belongs_to associations are now serialized as nil instead
of raise an error during serialization.
Merge pull request #708 from ride/fix-for-nil-associations

Handle correctly null associations
Add type when association name is different than objects type
Merge pull request #709 from ride/add-type

Add type key when association name is different than object type
Include 'linked' member for json-api collections

The options passed to the render are partitioned into adapter options
and serializer options. 'include' and 'root' are sent to the adapter,
not sure what options would go directly to serializer, but leaving this
in until I understand that better.