[Metrics] Class reduction similar to sklearn

[SkafteNicki]

What does this PR do?

Fixes #3035
Changes the reduction for accuracy, precision, recall, fbeta, f1 metrics to be similar to sklearn: default will be 'micro' (global measure) with the option of 'macro' (our old standard, unweighted mean of individual scores), 'weighted' (weigted mean of individual scores) and 'none' (return score for each class).

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[pep8speaks]

Hello @SkafteNicki! Thanks for updating this PR.

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2020-09-15 09:45:22 UTC

[mergify]

This pull request is now in conflict... :(

[codecov]

Codecov Report

Merging #3322 into master will increase coverage by 0%.
The diff coverage is 98%.

@@          Coverage Diff           @@
##           master   #3322   +/-   ##
======================================
  Coverage      90%     90%           
======================================
  Files         107     107           
  Lines        8149    8082   -67     
======================================
- Hits         7332    7307   -25     
+ Misses        817     775   -42     

[Borda]

LGTM

[mergify]

This pull request is now in conflict... :(

[Borda]

just extended the timeout, but not the tests are running super long, about month or two ago we hand testing in 8min, now 30 is not enough... :/

[SkafteNicki]

@Borda it seems on master that since commit 9e33a72 there is always 9 checks that is being cancelled because they take too long time (not that commit seems to influence this in any way)

[mergify]

This pull request is now in conflict... :(