disable propagation of loggers to ancestrors

[sdesrozis]

Fixes #1012

Description:

Disable propagation of loggers to ancestrors

# logger without propagation
logger = setup_logger("logger")
logger.info("message 1 from test logger") 

# logging creates root ancestor of all loggers excluded one above 
logging.info("message from default logging, a root logger is defined !")

# only logger dump because no longer propagation
logger.info("message 2 from test logger")

Result is

> 2020-05-05 09:24:27,583 logger INFO: message 1 from test logger
> 2020-05-05 09:24:27,583 logger INFO: message 2 from test logger

Check list:

• New tests are added (if a new feature is added)
• New doc strings: description and/or example code are in RST format
• Documentation is updated (if required)

[vfdev-5]

LGTM, thanks !