Easy tests reconst

[EmmaRenauld]

Quick description

Took a few minutes today to prepare some unit test in the reconst module.

Coverage of unit test changes (only; no script tests) are: reconst.fodf: from 0% to 36% reconst.frf: from 0% to 49%

Unchanged reconst files: reconst.aodf = 0% (@CHrlS98 if you want to contribute)! reconst.bingham = 88% (Thanks Charles) reconst.divide, reconst.mti, reconst.sh = 0% (@karanphil if you want to contribute!?) reconst.utils: 36%

Type of change

Check the relevant options.

• [x] Unit tests

Checklist

• [x] My code follows the style guidelines of this project (run autopep8)
• [ ] I added relevant citations to scripts, modules and functions docstrings and descriptions
• [x] I have performed a self-review of my code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [ ] My changes generate no new warnings
• [ ] I moved all functions from the script file (except the argparser and main) to scilpy modules
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 80.00000% with 4 lines in your changes are missing coverage. Please review.

Project coverage is 68.04%. Comparing base (deb254a) to head (3c87ad3).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #982 +/- ## ========================================== + Coverage 68.00% 68.04% +0.03% ========================================== Files 419 419 Lines 21569 21574 +5 Branches 3242 3244 +2 ========================================== + Hits 14668 14679 +11 + Misses 5609 5605 -4 + Partials 1292 1290 -2 ``` | [Components](https://app.codecov.io/gh/scilus/scilpy/pull/982/components?src=pr&el=components&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scilus) | Coverage Δ | | |---|---|---| | [Scripts](https://app.codecov.io/gh/scilus/scilpy/pull/982/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scilus) | `68.95% <ø> (-0.02%)` | :arrow_down: | | [Library](https://app.codecov.io/gh/scilus/scilpy/pull/982/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scilus) | `66.65% <80.00%> (+0.11%)` | :arrow_up: |