When i tried using Play WS library in a normal sbt project instead of play project I was bound to use play.api.Play.current and got java.lang.RuntimeException:
To use play-ws outside of play see "Using WSClient" section of documentation: http://www.playframework.com/documentation/2.3.x/ScalaWS
val builder = new com.ning.http.client.AsyncHttpClientConfig.Builder()
val client = new play.api.libs.ws.ning.NingWSClient(builder.build())
val response = client.url(url).get()