[EDP] Add an engine for a Spark standalone deployment

The Spark provisioning plugin allows the creation of Spark standalone
clusters in Sahara.  Sahara EDP should support running Spark
applications on those clusters.

blueprint edp-spark-standalone

Change-Id: I8cc62f1be61cfa3ce76be3b17f85f011e19bdc09
Merge "[EDP] Add an engine for a Spark standalone deployment"