implemented coreml exporter

[saad-palapa]

Code Pull Requests

Please provide the following:

TODO(saad)

• a clear explanation of what your code does
• if applicable, a reference to an issue
• a reproducible test for your PR (code, config and data sample)

Documentation Pull Requests

Note that the documentation HTML files are in docs/ while the Markdown sources are in mkdocs/docs.

If you are proposing a modification to the documentation you should change only the Markdown files.

api.md is automatically generated from the docstrings in the code, so if you want to change something in that file, first modify ludwig/api.py docstring, then run mkdocs/code_docs_autogen.py, which will create mkdocs/docs/api.md .

[github-actions]

Unit Test Results

  6 files  ±0    6 suites  ±0   13m 49s ⏱️ -34s
12 tests ±0    7 ✔️  -   2    5 💤 +  2  0 ❌ ±0 
60 runs  ±0  30 ✔️  - 12  30 💤 +12  0 ❌ ±0 

Results for commit b769b22. ± Comparison against base commit 5cf9110.

This pull request skips 2 tests.

tests.regression_tests.benchmark.test_model_performance ‑ test_performance[ames_housing.gbm.yaml]
tests.regression_tests.benchmark.test_model_performance ‑ test_performance[mercedes_benz_greener.gbm.yaml]

[alexsherstinsky]

@saad-palapa I cannot find any problems; I would only like to request -- if you do not mind -- to please add type hints, at least to the non-obvious variables and all return values of methods (for me, personally, I prefer them everywhere). Also, could someone else -- @arnavgarg1, @geoffreyangus, @justinxzhao please review? Thank you.

[alexsherstinsky]

Please add from __future__ import annotations at the very top followed by a blank line.

This will help modernize type hints (and make them easier to add -- without cyclical conflicts). Thank you!

[alexsherstinsky]

@saad-palapa I request one change and made one suggestion. Thank you so much for this addition!