Add a Spark job type for EDP

* Added support for JOB_TYPE_SPARK
* Modifed create_workflow_dir to not use job_workflow_postfix (only for hdfs)
* Rewrote unit tests in test_job.py to be oriented around
  validation behavior for classes of job types rather than
  features of validation, and included JOB_TYPE_SPARK.
* Moved test_job_executor_java.py into test_job_executor and added JOB_TYPE_SPARK
* Added tests for create_workflow_dir and upload_job_files

Partial-implements: blueprint edp-spark-job-type
Change-Id: Ifd91123afea9e921ac441751a37aa6afae0bbd66
Merge "Add a Spark job type for EDP"