Build #62

Parameters
 SPARK_BRANCH
Spark branch (e.g. branch-1.6 or master)
 SPARK_VERSION
Version to use when publishing (e.g. 1.4.0)
 GIT_REF
Branch, commit, or tag from which to cut release (e.g. branch-1.4, v1.4.1-rc1)
 SPARK_PACKAGE_VERSION
Identifier for the posted package (e.g. 1.4.0-rc1)