Small clarification fix for verification alg

[keykholt]

Description

In verification_decisions_trees.py, the code does not specify that the input data need to be in the [0,1] range. It also only permits one-hot vectors as inputs for y. I've made some small changes to check the input data range and to format the data if y is in the shape(nb_samples, 1)

Type of change

Please check all relevant options.

• Improvement (non-breaking)
• Bug fix (non-breaking)
• New feature (non-breaking)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[codecov-commenter]

Codecov Report

Merging #1890 (4559032) into dev_1.12.2 (dc29bbc) will decrease coverage by 9.61%.
The diff coverage is 50.00%.

@@              Coverage Diff               @@
##           dev_1.12.2    #1890      +/-   ##
==============================================
- Coverage       85.85%   76.23%   -9.62%     
==============================================
  Files             248      248              
  Lines           23312    23315       +3     
  Branches         4212     4213       +1     
==============================================
- Hits            20015    17775    -2240     
- Misses           2232     4614    +2382     
+ Partials         1065      926     -139     

Impacted Files	Coverage Δ
art/metrics/verification_decisions_trees.py	90.71% <50.00%> (-0.96%)	⬇️
art/attacks/evasion/carlini.py	7.55% <0.00%> (-86.74%)	⬇️
art/attacks/evasion/graphite/utils.py	10.37% <0.00%> (-79.25%)	⬇️
...s/extraction/functionally_equivalent_extraction.py	14.19% <0.00%> (-78.40%)	⬇️
art/attacks/evasion/decision_tree_attack.py	23.28% <0.00%> (-76.72%)	⬇️
art/attacks/evasion/graphite/graphite_blackbox.py	9.12% <0.00%> (-76.50%)	⬇️
...acks/evasion/graphite/graphite_whitebox_pytorch.py	9.85% <0.00%> (-75.87%)	⬇️
art/attacks/extraction/knockoff_nets.py	20.13% <0.00%> (-69.80%)	⬇️
art/attacks/evasion/adversarial_patch/utils.py	11.53% <0.00%> (-69.24%)	⬇️
art/attacks/evasion/hclu.py	30.90% <0.00%> (-69.10%)	⬇️
... and 21 more

[lgtm-com]

This pull request introduces 1 alert when merging 535e305 into dc29bbc - view on LGTM.com

new alerts:

• 1 for Unreachable code

[lgtm-com]

This pull request introduces 2 alerts when merging 4559032 into dc29bbc - view on LGTM.com

new alerts:

• 2 for Wrong name for an argument in a call

[beat-buesser]

Hi @keykholt Thank you very much! It looks good to me.