title: Abstract method error when combining akka 2.3.7, reactive mongo and spray
body: <p>Application dependencies are:</p>
  
  <pre><code>com.typesafe.akka#akka-actor_2.10;2.3.7
  org.reactivemongo#reactivemongo_2.10:0.10.5.0.akka23
  org.reactivemongo#play2-reactivemongo_2.10:0.10.5.0.akka23
  </code></pre>
  
  <p>and a couple of spray libs all of version 1.3.1
  When starting the appliction I get</p>
  
  <pre><code>java.lang.AbstractMethodError
      at akka.actor.ActorCell.create(ActorCell.scala:580)
      at akka.actor.ActorCell.invokeAll$1(ActorCell.scala:456)
      at akka.actor.ActorCell.systemInvoke(ActorCell.scala:478)
      at akka.dispatch.Mailbox.processAllSystemMessages(Mailbox.scala:279)
      at akka.dispatch.Mailbox.run(Mailbox.scala:220)
      at akka.dispatch.Mailbox.exec(Mailbox.scala:231)
      at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260)
      at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339)
      at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979)
      at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)
  </code></pre>
  
  <p>PS: I do not use any akka 2.2 compatible libs and I did read similar topics here(the only solution there was to update play from 2.2 to 2.3)</p>