Bump version to 1.3.0.beta
Use multi_json on the Collection as well as on the resources.  This unmasks a mysterious bug where calling #to_json on a Collection throws an undefined method 'to_json' error if the json gem is not included, which looks like the method doesn't exist on the Collection, but in fact is coming from inside dm-serializer
Merge pull request #24 from d11wtq/bugfix/to_json_deps

Use multi_json on the Collection as well as on the resources.
Remove jeweler
Remove VERSION file
Bump multi_json dependency to ~> 1.3.2
Silence deprecation warnings for ViolationSet#errors
prevent quoted nulls ("null") when to_json is called on nil relationship