Changes for akka 2.4.11

Changes for akka 2.4.11

- Fixed compile error in MeteringBehavior as signature of onReceive now
  declares Throwable.

- Fixed intermittent failure in
  ShardManagerGetSnapshotReplyActorTest#testGetSnapshotTimeout. On failure,
  the actor would not get the ReceiveTimeout message from akka. However,
  oddly the test didn't fail if just testGetSnapshotTimeout was run - it
  would only fail if run with at least one of the other 2 tests. I tried
  creating a different ActorSystem for each test but that didn't fix it.
  I finally narrowed it down to creating the actors via the TestActorFactory
  although the exact reason is unknown. The tests don't really need to use
  the TestActorFactory so I remove its use.

- Fixed intermittent failure in
  ShardTransactionTest#testShardTransactionInactivity. This was the same issue
  as the ShardManagerGetSnapshotReplyActorTest, i.e. the actor would not get
  the ReceiveTimeout message when no other message was sent. I found the
  TestActorFactory was again the culprit. I narrowed it down to the
  verifyActorReady method which creates an ActorSelection and sends an
  Identify message. This was put in to work around messages intermittently
  going to dead letters shortly after actor creaton. It seems this code
  somehow may interfere with the ReceiveTimeout functionality. So to workaround
  this, I allowed the caller to elide the verifyActorReady call.

Change-Id: Ic8474def917414fa9bbe0f19b30b213f3052a1aa
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>