discard log messages in tests to keep output clean
marshal single structs as object at root level fixes #12
correct a single unmarshal test

when posting single objects, they must be in a object, this already
works, i just wanted to confirm the behavior, see:
http://jsonapi.org/format/#crud-creating-individual-resources
Merge pull request #55 from univedo/bugfixRootObject

Bugfix root object