Added a failing test for multiple find() calls for the same id
Add ActiveModelAdapter and Serializer
Document the AMS adapter
Move everything to a package
Update TRANSITION.md

Added some clarification around ActiveModelSerializer terminology.
Add metadataFor
Add some basic docs
Override normalizeRelationships to extract polymorphic type correctly
Fixes fetches in the loading state

Fixes #1281 Fixes #1280
Merge branch 'andrei1089-master'