Support loggers in verbose mode

[jacksonllee]

Thank you for this wonderful library!

A print statement is used for the various CleverCSV functions where one can set verbose=True, but a logger is sometimes preferred (if not necessary, especially in a production environment) for its flexibility in stream handling and other features unavailable to print statements. This pull request adds a logger keyword argument alongside the existing verbose, so that a logging.Logger instance can be passed in and used. No code changes are made under clevercsv/console/, as the logger doesn't appear to be relevant to the console use cases.