Python/PySpark: Logger doesn't implement 'isatty()'

When attempting to use H2O from Zeppelin, paragraphs fail with
AttributeError: 'Logger' object has no attribute 'isatty', due to Zeppelin using a custom class to capture output and redirect it.

While adding a stub method to return false is possible (similar to what was done previously for ZEPPELIN-734), I think it would be better to have Logger inherit from a TextIO class and override the write method, increasing compatibility with libraries that use stdout.