code: def auth_delete_creds(self, username=None):
  		
  		if not username:
  			self.__config['basic_auth'] = {}
  			self.logger.info('basic authentication database has been cleared of all entries')
  			return
  		del self.__config['basic_auth'][username]
docs: Delete the credentials for a specific username if specified or all
  		stored credentials.
  
  		:param str username: The username of the credentials to delete.