Create ML Flow Python logging handler

[stevehadd]

General good practice for logging in python code is to pass all messages through the central logging module, and provide handlers as outputs, which are often a StreamHandler to go to the console and a FileHandler to go to a text file. It would be good to extend file handler so that at the end of a run, the file contain the logs is logged with MLflow as an artifact. My invesatigations show that ML Flow does not capture stdout/stderr by default, and this would be a good way to continue python best practice into ML projects