shappley

Expose underlying slf4j Logger

3

Updates `util.Logger` to expose the underlying `slf4j.Logger` instance. This is beneficial for those with projects with several SLF4J Loggers, and follows the pattern in the [scala-logging project](https://github.com/lightbend-labs/scala-logging/blob/main/src/main/scala/com/typesafe/scalalogging/Logger.scala#L82).