resolver-fix

[Naina-Gurung]

plugins.sbt has a resolver pointing to https://dl.bintray.com/spark-packages/maven but this website is forbidden.
To create a jar from this repo, it throws an error - Resolver Exception - sbt-spark-package 0.2.4 not found.

Solution - To update the plugins.sbt with repos.spark-packages,org instead of the dl.bintray.com/spark-packages/maven".
PR raised with the resolution - #69