GridREx is not tested!

[MatteoMagnini]

I have tried to use GridREx to extract rules in a regression task, however it rises an error:

File "/opt/homebrew/Caskroom/miniforge/base/envs/prima/lib/python3.9/site-packages/psyke/init.py", line 251, in extract
return self._extract(data, mapping)
File "/opt/homebrew/Caskroom/miniforge/base/envs/prima/lib/python3.9/site-packages/psyke/extraction/hypercubic/gridex/init.py", line 32, in _extract
return self._create_theory(dataframe)
File "/opt/homebrew/Caskroom/miniforge/base/envs/prima/lib/python3.9/site-packages/psyke/extraction/hypercubic/init.py", line 67, in _create_theory
body = cube.body(variables, self._ignore_dimensions(), self.unscale, self.normalization)
File "/opt/homebrew/Caskroom/miniforge/base/envs/prima/lib/python3.9/site-packages/psyke/extraction/hypercubic/hypercube.py", line 292, in body
list(variables.values()), [to_rounded_real(v) for v in coefs],
File "/opt/homebrew/Caskroom/miniforge/base/envs/prima/lib/python3.9/site-packages/psyke/extraction/hypercubic/hypercube.py", line 292, in
list(variables.values()), [to_rounded_real(v) for v in coefs],
File "/opt/homebrew/Caskroom/miniforge/base/envs/prima/lib/python3.9/site-packages/psyke/utils/logic.py", line 159, in to_rounded_real
return real(round(n, PRECISION))
TypeError: type numpy.ndarray doesn't define round method

I have an idea to solve it, however I have found out that the algorithm lacks tests! This is an issue of paramount importance that should be addressed asap.