Fix for when using custom embedded key for a hasMany relationship.
Fix polymorphic test name
don't delete un-normalized key
Merge pull request #86 from toranb/custom-hasmany-key

Add custom key support for hasMany relationships
Set errors on model

This makes it possible to handle server side errors on the client side.

Function was copied from the ActiveModelAdapter (https://github.com/emberjs/data/blob/v1.0.0-beta.8/packages/activemodel-adapter/lib/system/active_model_adapter.js#L102) and modified to work with DRF.
Fixed test
Merge pull request #88 from chripede/patch-1

Set errors on model