[CORE] [SPARK-9760] Use Option instead of Some for Ivy repos

This was introduced in apache#7599

cc rxin brkyvz

Author: Shivaram Venkataraman <shivaram@cs.berkeley.edu>

Closes apache#8055 from shivaram/spark-packages-repo-fix and squashes the following commits:

890f306 [Shivaram Venkataraman] Remove test case
51d69ee [Shivaram Venkataraman] Add test case for --packages without --repository
c02e0b4 [Shivaram Venkataraman] Use Option instead of Some for Ivy repos

core/src/main/scala/org/apache/spark/deploy/SparkSubmit.scala

@@ -284,7 +284,7 @@ object SparkSubmit {
         Nil
       }
     val resolvedMavenCoordinates = SparkSubmitUtils.resolveMavenCoordinates(args.packages,
-      Some(args.repositories), Some(args.ivyRepoPath), exclusions = exclusions)
+      Option(args.repositories), Option(args.ivyRepoPath), exclusions = exclusions)
     if (!StringUtils.isBlank(resolvedMavenCoordinates)) {
       args.jars = mergeFileLists(args.jars, resolvedMavenCoordinates)
       if (args.isPython) {