Create a logging helper class

[arthurazs]

This is an ideia.

Description

Create a helper class to manage the app's logging.

Example:

def _critical(self, msg, err):
    self.logger.error(msg)
    self.logger.critical('{}: {}'.format(err.__class__.__name__, err))
    raise SystemExit(-1)

This is from model.py but could be used by other classes as well.

[arthurazs]

Add DEBUG