chore: add bare-minimum logging support

Follow the Python documentation guidelines for "Configuring Logging for a Library" [1]

Which is adding these two lines: import logging logging.getLogger(name).addHandler(logging.NullHandler())

Setup a very basic usage of logging in gitlab/client.py

By using the NullHandler it means that by default any log messages output will not be displayed. It is up to the client application to do a logging.basicConfig() call to get log messages to display.

[1] https://docs.python.org/3/howto/logging.html#configuring-logging-for-a-library Related: #2080

Codecov Report

Merging #2204 (b476afe) into main (7a8a862) will increase coverage by 0.00%. The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #2204   +/-   ##
=======================================
  Coverage   96.18%   96.18%           
=======================================
  Files          87       88    +1     
  Lines        5683     5692    +9     
=======================================
+ Hits         5466     5475    +9     
  Misses        217      217           

Flag	Coverage Δ
api_func_v4	82.53% <90.00%> (+0.02%)	:arrow_up:
cli_func_v4	83.01% <90.00%> (+0.02%)	:arrow_up:
unit	87.66% <100.00%> (+0.01%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
gitlab/__init__.py	100.00% <100.00%> (ø)
gitlab/_logging.py	100.00% <100.00%> (ø)
gitlab/client.py	98.80% <100.00%> (+<0.01%)	:arrow_up:

I think it worth adding this feature to the features list mentioned in the README

Integration tests would probably help us figure out what actually happens when the library is being used by an application. More than that, it will provide us the confidence that what happens is exactly what we expect it to do. WDYT?