crossbuild scala 2.11 & play 2.3 - WIP
remove custom WS implementation, use play-ws 2.3 instead
Merge branch 'master' of github.com:prismicio/scala-kit into scala211

* 'master' of github.com:prismicio/scala-kit:
  Expose slug in LinkedDocument
  Expose ref id
  Linked documents now belong to Document itself
  Publish 1.0-M14
  Expose linked docs
update tests
scala 2.11 / play 2.3.1