Get unit testing back

[mkruckow]

We are saying for a long time, that we'd like to get the unit testing back.

Here we may want to have a list of stuff to be done for this (I'll start):

• there is no test grid: posydon/tests/data/POSYDON-UNIT-TESTS/visualization/grid_unit_test_plot.h5
  This causes a ValueError: Test grid for unit testing was not found! when trying to do either of the following imports:

import posydon.tests.binary_evol.test_BinaryStar
import posydon.tests.binary_evol.test_SingleStar
import posydon.tests.visualization.test_plot1D
import posydon.tests.visualization.test_plot2D
import posydon.tests.binary_evol.SN.test_profile_collapse

[ssbvr]

I also suggest enforcing a code formatting convention. Everyone can adopt this if they come in a .vs_code file. I think it's a good idea to trigger the formation when saving a file. When this is in place and POSYDON has been reformatted, add stylistic automatic checks with a GitHub action so that future code will comply with the coding convention.

[mkruckow]

Here a progress list:

• code files in the base posydon: config.py
• [in progress] code files in bin -> move code to utils
• code files in active_learning
• code files in binary_evol
• code files in grids
• code files in interpolation
• [in progress] code files in popsyn
• code files in utils
• code files in visualization

[sgossage]

@elizabethteng is working on PR#499 for unit tests in the popsyn module. Unit tests for the other modules have yet to be assigned.

We have decided however that further development on unit tests beyond popsyn are a low priority at the moment.

[astroJeff]

Converting from an issue to discussion. The question of how careful and complete we want our unit tests to be is a nuanced one