Add MLSMOTE algorithm to imblearn

[balvisio]

What does this implement/fix? Explain your changes.

This is an implementation of the Multilabel SMOTE (MLSMOTE) algorithm described in the paper:

Charte, F. & Rivera Rivas, Antonio & Del Jesus, María José & Herrera, Francisco. (2015). MLSMOTE: Approaching imbalanced multilabel learning through synthetic instance generation. Knowledge-Based Systems. -. 10.1016/j.knosys.2015.07.019.

It is an oversampling technique that AFAIK there is no open-source implementation yet.

Addresses: #340

Any other comments?

The implementation is ready to be reviewed. Once reviewed, I can squash the commits for cleaner history.

[codecov]

Codecov Report

Base: 97.19% // Head: 93.33% // Decreases project coverage by -3.86% ⚠️

Coverage data is based on head (70e1f96) compared to base (6176807).
Patch coverage: 95.11% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #927      +/-   ##
==========================================
- Coverage   97.19%   93.33%   -3.87%     
==========================================
  Files          97       96       -1     
  Lines        6348     6422      +74     
  Branches      711      582     -129     
==========================================
- Hits         6170     5994     -176     
- Misses        106      363     +257     
+ Partials       72       65       -7     

Impacted Files	Coverage Δ
imblearn/over_sampling/_mlsmote.py	92.25% <92.25%> (ø)
imblearn/over_sampling/__init__.py	100.00% <100.00%> (ø)
imblearn/over_sampling/tests/test_mlsmote.py	100.00% <100.00%> (ø)
imblearn/keras/tests/test_generator.py	7.93% <0.00%> (-92.07%)	⬇️
imblearn/tensorflow/_generator.py	35.48% <0.00%> (-61.40%)	⬇️
imblearn/tests/test_docstring_parameters.py	30.93% <0.00%> (-56.84%)	⬇️
imblearn/tensorflow/tests/test_generator.py	10.75% <0.00%> (-54.84%)	⬇️
imblearn/keras/_generator.py	47.36% <0.00%> (-44.74%)	⬇️
imblearn/datasets/tests/test_zenodo.py	89.18% <0.00%> (-2.71%)	⬇️
imblearn/pipeline.py	93.47% <0.00%> (-1.09%)	⬇️
... and 4 more

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[rjurney]

@balvisio Thank you! You are a scholar and a gentleman.

[balvisio]

thank you @rjurney , my pleasure. Looking forward to any feedback.

[h-holm]

Thanks for the great work, @balvisio! Do we have any news on this PR?

[balvisio]

Hello @h-holm , thank you. I am waiting for the maintainers to review the code so that the PR can be merged.

[h-holm]

Thanks for the update, @balvisio. Crossing my fingers that @glemaitre and others can chip in when time allows, as this would be a great addition 🤞