Maintenance/release scala 0.2.0 b2 snapshot

[jamie256]

Description

Add Scala Ranking Metrics support

// with a Dataframe containing integer predictions indexes and target indexes
val session = df.newProfilingSession("RankingMetricsTest")
  .withRankingMetrics(predictionField="predictions", targetField="labels", k=Some(2))
  
session.logRankingMetrics(timestamp=dataset_timestamp,
          orgId = "replace-with-org-id",
          modelId = "replace-with-model-id",
          apiKey = "replace-with-api-key")  

• [ ] I have reviewed the Guidelines for Contributing and the Code of Conduct.