Netty ByteBuf leak on AkkaHttpWebSocketSpec

> testOnly play.it.http.websocket.AkkaHttpWebSocketSpec 

[info] AkkaHttpWebSocketSpec
[info] 
[info] Plays WebSockets should
[info]   allow handling WebSockets using Akka streams
[info]     + allow consuming messages
[info]     + allow sending messages
[info]     + close when the consumer is done
[info]     + allow rejecting a websocket with a result
[info]     + aggregate text frames
[info]     + aggregate binary frames
[info]     + close the websocket when the buffer limit is exceeded
[info]     + close the websocket when the wrong type of frame is received
[info]     + respond to pings
[info]     + not respond to pongs
[info]   allow handling WebSockets using iteratees
[info]     + allow consuming messages
[info]     + allow sending messages
[info]     + close when the consumer is done
[info]     + clean up when closed
[info]     + allow rejecting a websocket with a result
[info]   allow handling a WebSocket with an actor
[info]     + allow consuming messages
[info]     + allow sending messages
[info]     + close when the consumer is done
[info]     + clean up when closed
[error] i.n.u.ResourceLeakDetector - LEAK: ByteBuf.release() was not called before it's garbage-collected. Enable advanced leak reporting to find out where the leak occurred. To enable advanced leak reporting, specify the JVM option '-Dio.netty.leakDetection.level=advanced' or call ResourceLeakDetector.setLevel() See http://netty.io/wiki/reference-counted-objects.html for more information.
[info]     + allow rejecting a websocket with a result
[info]   allow handling a WebSocket in java
[info]     + allow consuming messages
[info]     + allow sending messages
[info]     + close when the consumer is done
[info]     + allow rejecting a websocket with a result
[info]   allow handling a WebSocket using legacy java API
[info]     + allow consuming messages
[info]     + allow sending messages
[info]     + clean up when closed
[info]     + allow rejecting a websocket with a result
[info]     + allow handling a websocket with an actor
[info] 
[info] Total for specification AkkaHttpWebSocketSpec
[info] Finished in 2 seconds, 639 ms
[info] 29 examples, 0 failure, 0 error
[info] 
[info] Passed: Total 29, Failed 0, Errors 0, Passed 29
[success] Total time: 80 s, completed Dec 14, 2015 6:36:09 PM