ActiveModelSerializers

There's been a lot of churn around AMS since it began back in Rails 3.2 and a lot of new libraries are around and the JSON:API spec has reached 1.0. If there is to be a 1.0 release of AMS, it will need to address the general needs of serialization in much the way ActiveJob can be used with different workers. The next major release is in development. We're starting simple and avoiding, at least at the outset, all the complications in AMS version, especially all the implicit behavior from guessing the serializer, to the association's serializer, to the serialization type, etc. The basic idea is that models to serializers are a one to many relationship. Everything will need to be explicit. If you want to serialize a User with a UserSerializer, you'll need to call it directly. The serializer will essentially be for defining a basic JSON:API resource object: id, type, attributes, and relationships.