Changed function arguments throughout pycytominer from str 'none' to None

[kenibrewer]

Description

This is a code refactoring change suggested for inclusion prior to 1.0 release that adopts the more pythonic use of None arguments instead of strings set to "none".

What is the nature of your change?

• Bug fix (fixes an issue).
• Enhancement (adds functionality).
• Breaking change (fix or feature that would cause existing functionality to not work as expected).
• This change requires a documentation update.

Checklist

Please ensure that all boxes are checked before indicating that a pull request is ready for review.

• I have read the CONTRIBUTING.md guidelines.
• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.
• New and existing unit tests pass locally with my changes.
• I have added tests that prove my fix is effective or that my feature works.
• I have deleted all non-relevant text in this pull request template.

[codecov-commenter]

Codecov Report

Merging #293 (c9c175f) into master (921dcfe) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #293   +/-   ##
=======================================
  Coverage   95.12%   95.12%           
=======================================
  Files          57       57           
  Lines        3057     3057           
=======================================
  Hits         2908     2908           
  Misses        149      149           

Flag	Coverage Δ
unittests	95.12% <100.00%> (ø)

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

Impacted Files	Coverage Δ
pycytominer/cyto_utils/write_gct.py	100.00% <ø> (ø)
pycytominer/tests/test_annotate.py	100.00% <ø> (ø)
pycytominer/tests/test_normalize.py	100.00% <ø> (ø)
pycytominer/aggregate.py	96.77% <100.00%> (ø)
pycytominer/annotate.py	96.42% <100.00%> (ø)
pycytominer/consensus.py	100.00% <100.00%> (ø)
pycytominer/cyto_utils/DeepProfiler_processing.py	93.02% <100.00%> (ø)
pycytominer/cyto_utils/cells.py	96.00% <100.00%> (ø)
pycytominer/feature_select.py	94.44% <100.00%> (ø)
pycytominer/normalize.py	100.00% <100.00%> (ø)
... and 1 more

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[gwaybio]

LGTM! Thanks for making this fix @kenibrewer - it was very much needed!

[gwaybio]

Please merge this with #291 and then I will squash and merge

[kenibrewer]

@gwaybio Merging pre-commit all branch resolved the unexpected diffs. This is ready for merge.