[Feature Request] Allow Path objects for evaluate data and output_path parameters

[pamelafox]

Currently the types for evaluate function are:

def evaluate(
    *,
    evaluation_name: Optional[str] = None,
    target: Optional[Callable] = None,
    data: Optional[str] = None,
    evaluators: Optional[Dict[str, Callable]] = None,
    evaluator_config: Optional[Dict[str, Dict[str, str]]] = {},
    tracking_uri: Optional[str] = None,
    output_path: Optional[str] = None,
    **kwargs,
):

However, many Python developers use Path objects to represent paths. It'd be nice to be able to directly pass those in to data and output_path. For now, I am casting them to strings with str().