Upgrade sbt-assembly (#369)
Upgrade sbt-assembly (#369)

Without this upgrade shading was not working properly for me when
developing locally.  The shaded classes where getting repackaged but
the unshaded classes where not updates to to the repackaged classes.
GoogleCloudDataproc/spark-bigquery-connector,GoogleCloudDataproc/spark-bigquery-connector,GoogleCloudDataproc/spark-bigquery-connector