v1.3.0

Serialization refactoring (#53)

When rendering relationships without a data component the relationship
is not serialized in the right location in the document.
* Add `ResourceRelationshipConverter` to allow easier identification of relationships without any data
* Significant clean up the `ResourceObjectConvertor` logic removing the dependency on probes.
* Relationship/Attribute distinction is now done up front removing necessity of `JsonWriterCapture`
* Add non generic `Relationship` to allow definition of relationship with data (e.g. only links)
* Add checks that will throw an error if a explicitly defined relationship or document-root does not contain resource objects