Python(chore): remove default logger configuration to leave to implementation

[alexluck-sift]

Removes the logger configuration such that it can be exclusively defined by the customer code.

For example:

import logging
from sift_client import SiftClient

# Configure logging
logging.basicConfig(level=logging.INFO)

# Fine-grained control
logging.getLogger('sift_client').setLevel(logging.DEBUG)                    # All sift_client logs
logging.getLogger('sift_client.resources').setLevel(logging.WARNING)       # Only resource logs  
logging.getLogger('sift_client.resources.assets').setLevel(logging.ERROR)  # Only asset logs
logging.getLogger('sift_client.transport').setLevel(logging.INFO)          # Only transport logs

client = SiftClient(...)

[nathan-sift]

lgtm. The feedback on the NullHandler is optional