Bump sbt to 1.5.6
Bump sbt to 1.5.6

updates log4j 2 to 2.15.0, which fixes remote code execution vulnerability ([CVE-2021-44228](https://github.com/advisories/GHSA-jfh8-c2jp-5v3q))

JohnSnowLabs/spark-nlp,JohnSnowLabs/spark-nlp,JohnSnowLabs/spark-nlp,JohnSnowLabs/spark-nlp