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