Travis failed on "start a repl session using the rsc"

• start a repl session using the rsc *** FAILED *** (37 seconds, 374 milliseconds)
  java.lang.RuntimeException: java.util.concurrent.TimeoutException
  at org.apache.livy.rsc.Utils.propagate(Utils.java:60)
  at org.apache.livy.rsc.RSCClient.stop(RSCClient.java:228)
  at org.apache.livy.repl.ReplDriverSuite$$anonfun$1.apply$mcV$sp(ReplDriverSuite.scala:64)
  at org.apache.livy.repl.ReplDriverSuite$$anonfun$1.apply(ReplDriverSuite.scala:40)
  at org.apache.livy.repl.ReplDriverSuite$$anonfun$1.apply(ReplDriverSuite.scala:40)
  at org.scalatest.Transformer$$anonfun$apply$1.apply$mcV$sp(Transformer.scala:22)
  at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
  at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
  at org.scalatest.Transformer.apply(Transformer.scala:22)
  at org.scalatest.Transformer.apply(Transformer.scala:20)
  ...
  Cause: java.util.concurrent.TimeoutException:
  at io.netty.util.concurrent.AbstractFuture.get(AbstractFuture.java:56)
  at org.apache.livy.rsc.RSCClient.stop(RSCClient.java:223)
  at org.apache.livy.repl.ReplDriverSuite$$anonfun$1.apply$mcV$sp(ReplDriverSuite.scala:64)
  at org.apache.livy.repl.ReplDriverSuite$$anonfun$1.apply(ReplDriverSuite.scala:40)
  at org.apache.livy.repl.ReplDriverSuite$$anonfun$1.apply(ReplDriverSuite.scala:40)
  at org.scalatest.Transformer$$anonfun$apply$1.apply$mcV$sp(Transformer.scala:22)
  at org.scalatest.OutcomeOf$class.outcomeOf(OutcomeOf.scala:85)
  at org.scalatest.OutcomeOf$.outcomeOf(OutcomeOf.scala:104)
  at org.scalatest.Transformer.apply(Transformer.scala:22)
  at org.scalatest.Transformer.apply(Transformer.scala:20)

please reference to https://travis-ci.org/runzhiwang/incubator-livy/jobs/579610195