Update spark-core, spark-mllib to 2.4.4
Update spark-core, spark-mllib to 2.4.4

transcendent-ai-labs/DynaML,transcendent-ai-labs/DynaML,transcendent-ai-labs/DynaML,transcendent-ai-labs/DynaML,mandar2812/DynaML,transcendent-ai-labs/DynaML,mandar2812/DynaML