Newer versions of the library on maven central

### System Information

- spark_2.2.0-1.2.5
- Spark 2.3 and later

### Describe the problem
EMR clusters which use spark 2.3 and later have newer versions of sagemaker spark jars.

However they are not available on maven central : https://mvnrepository.com/artifact/com.amazonaws/sagemaker-spark

When is the plan to release to maven central for spark 2.3 and later? Or any recommendations for running on later EMR versions of the cluster.

### Minimal repo / logs

Start by reviewing the sagemaker-spark release and publishing setup, then compare the versions available on Maven Central with the Spark 2.3-and-later and EMR versions described in the issue. The issue names no source files or tests; done would mean confirming a supported release path or documenting recommendations for later EMR clusters.

Written by the indexing model from the issue text.