Major Description
Samza always submits its jobs to YARN's default queue. We should make this configurable.
I believe that the steps are:
1) Add a `yarn.queue` field to YarnConfig.
2) Update YarnJob.scala's submit() method to get the yarn queue, and use it in the client.submitApplication() call.
3) Update ClientHelper.scala's submitApplication() method to take an optional queue, and if it's set, add it to the ApplicationSubmissionContext, as I described above.