Tracking Artifacts as well along with metrics and parameters in Mlflow
**Is your feature request related to a problem? Please describe.**

While we are training ASR model on nemo framework, we are able to track parameters and metrics with minimal inputs in the config.sh. But we are not able to track artifacts i.e. Nothing getting stored here.

**Describe the solution you'd like**
`exp_manager:
    ...
    create_checkpoint_callback: True
    create_mlflow_logger: True
    mlflow_logger_kwargs:
        experiment_name: ${name}
        tags:
            <Any key:value pairs>
        save_dir: './mlruns'
        prefix: ''
        artifact_location: None
        # provide run_id if resuming a previously started run
        run_id: Optional[str] = None`

Tracking artifacts would be really helpful along with metrics and parameters. Thanks in advance!


