LNT: Add pylint & address issues

[snowman2]

• Fully documented, including history.rst for all changes and api/*.rst for new API

[codecov]

Codecov Report

Merging #909 (8fc174c) into master (f1f784a) will increase coverage by 0.57%.
The diff coverage is 98.31%.

@@            Coverage Diff             @@
##           master     #909      +/-   ##
==========================================
+ Coverage   95.60%   96.18%   +0.57%     
==========================================
  Files          21       21              
  Lines        1730     1755      +25     
==========================================
+ Hits         1654     1688      +34     
+ Misses         76       67       -9     

Impacted Files	Coverage Δ
pyproj/_show_versions.py	86.04% <ø> (ø)
pyproj/crs/coordinate_operation.py	100.00% <ø> (ø)
pyproj/enums.py	100.00% <ø> (ø)
pyproj/transformer.py	94.68% <95.65%> (+0.02%)	⬆️
pyproj/__main__.py	98.27% <96.77%> (+0.09%)	⬆️
pyproj/utils.py	82.45% <97.14%> (+0.97%)	⬆️
pyproj/geod.py	97.38% <98.68%> (+6.16%)	⬆️
pyproj/__init__.py	89.47% <100.00%> (ø)
pyproj/aoi.py	100.00% <100.00%> (ø)
pyproj/crs/__init__.py	100.00% <100.00%> (ø)
... and 6 more

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