Merlin-spellbook

Added
- Added support for python 3.12 and python 3.13

Changed
- Dropped support for python 3.7 and older
- Updated Makefile to use newer check-style targets

Fixed
- style and version number
- testing for make-samples

Added
- -round and -repeat options to make-samples, which allows for mixed integers and floats

Changed
- changed python version support to 3.7 - 3.11 (3.6 is past end-of-life)

Fixed
- `learn.make_regressor` and `learn_alt.random_forest` properly calls `utils.load_infile`.

Fixed
- `make-barrier-qoi` can accept no constraints.
- `make-barrier-qoi` applies `numpy.atleast_2d` to the qoi before returning.
- `make-barrier-qoi` correctly normalizes inputs from 0 to 1.
- `utils.stack_arrays` returns inputs in correct shape: ( of features, dim of feature).
- `ml.learn` and `ml.learn_alt` use correct `load_infiles` function from `utils`.

Fixed
- Add missing __init__.py to optimization module.

Changed
- Remove .keepme file in optimization module.