Fixed model error and changed code to set run without symlink

[raphaelshirley]

Closes #36

We should perhaps set the link to the run directory in a more robust way. currently I get it from the default work directory and go up a level to runs. We also might wnat to make it overwritable in the estimator so that the folder can be moved between systems

Using the symlinked $cache/lephare/work directory creates the possibility of two informers using it simultaneously and intereferring with the default location during local runs. rail_lepahre should use completely independent work directories using the informer name.

Code Quality

• [x] My code follows the code style of this project
• [x] I have written unit tests or justified all instances of #pragma: no cover; in the case of a bugfix, a new test that breaks as a result of the bug has been added
• [x] My code contains relevant comments and necessary documentation for future maintainers; the change is reflected in applicable demos/tutorials (with output cleared!) and added/updated docstrings use the NumPy docstring format
• [x] Any breaking changes, described above, are accompanied by backwards compatibility and deprecation warnings

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 72.72727% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 91.93%. Comparing base (e5c47db) to head (52ded5c). Report is 23 commits behind head on main.

Files	Patch %	Lines
src/rail/estimation/algos/lephare.py	72.72%	3 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #37 +/- ## =========================================== - Coverage 100.00% 91.93% -8.07% =========================================== Files 1 2 +1 Lines 8 124 +116 =========================================== + Hits 8 114 +106 - Misses 0 10 +10 ```

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