Fixing issue with Spark version resolution on EMR (#381)

* Added unit tests for hmac options. Updated error messages.

* Moved int casting to be done inside the length check.

connector/src/main/scala/com/vertica/spark/datasource/v2/VerticaDatasourceV2Table.scala

@@ -88,13 +88,16 @@ class VerticaTable(caseInsensitiveStringMap: CaseInsensitiveStringMap, readSetup
  }
  logger.debug("Config loaded")
 
- // Pushdown of aggregates added in spark 3.2, detect spark version so we return class with right feature support
+ // Aggregates push down were added in spark 3.2. We detect spark version here to return the compatible class
  var sparkNewerThan31 = true
  try {
- val sparkVersion = SparkSession.getActiveSession.get.version
- val versionList = sparkVersion.split("\\.").map(_.toInt)
- if(versionList.length >= 2 && versionList(0) == 3 && versionList(1) < 2) {
- sparkNewerThan31 = false
+ val versionList = SparkSession.getActiveSession.get.version.split("\\.")
+ if (versionList.length >= 2) {
+ val major = versionList(0).toInt
+ val minor = versionList(1).toInt
+ if (major == 3 && minor < 2) {
+ sparkNewerThan31 = false
+ }
  }
  }
  catch { // Couldn't recgonize version string, assume newer version