Support for multi Scala version & updated Spark-network commons to the latest version

[prassee]

This PR brings the following features :-

• support for Scala 2.12 & latest Spark network commons 2.4
• changes in build.sbt to support both 2.11 & 2.12 versions of Scala
• renamed package from com.* to net.*
• added new dependency to support net.neoremind.kraps.serializer package since the package moved to a new artifact called spark-tags
• 🚧 completely got rid of maven build support in favor of sbt. Though this has been discussed in my previous PR. Iam suggesting again for the following reasons :
  • sbt has support for delivering artifacts for multiple Scala version
  • easy to manage ,since sbt can publish maven artifacts as well