controller: Does not setup email logging on empty user/password strings

## Notebooks

* `baseline_condenser`: Using a feedback controller without machine learning to test control of HVAC systems.

* `baseline_condenser`: Using a feedback controller without machine learning to test control of HVAC systems. This is the demo notebook for `baseline_control.SimpleFeedbackController`.

* `Models-v2`: Generating data-driven models from the [`v2` dataset][2], which has been preprocessed. See `docs/datasets/v1/` for more information.

    settings = {}

    settings.update(vars(parsed_args))

    # try reading them, if error, return previous settings

    cfg = ConfigParser()

    cfg = ConfigParser(allow_no_value=True)

    if parsed_args.settings is None:

        raise ValueError('No settings file provided.')

    cfg.read(parsed_args.settings)

        mailhost is not None and \

        fromaddr is not None and \

        len(toaddrs) > 0 and toaddrs[0]!='' and \

        username is not None and password is not None):

        username not in ('', None) and password not in ('', None)):

        logger.info('Setting up email logging.')

        class EmailHandler(BufferingHandler):