Non-canonical sbt projects

[pdmack]

The Scala S2I builder assemble script scans projects for a build.sbt and a projects directory and exits if it doesn't find them. However, there are older projects such as:
https://github.com/databricks/spark-perf/tree/master/spark-tests
which can potentially be built using sbt if we view our S2I as a generic sbt builder.

The trouble is that it obviates the value of a radanalytics openshift-spark image which includes Spark 2.x, and in turn the S2I images that use it (only Scala the moment).

Perhaps it is enough to just add a build parameter that relaxes the noted strict requirement.