Increase Test Coverage

**Is your feature request related to a problem? Please describe.**

[](https://codecov.io/gh/AdityaNG/kan-gpt)
The current code test coverage is at around 60%, it would be good to have test cases to cover at least 80% of the code to ensure there are minimal regressions.

**Describe the solution you'd like**
We can see which files and which lines are covered by the existing test cases (which is defined in `tests/`) by clicking on the code coverage badge on the README or following this link:
https://codecov.io/gh/AdityaNG/kan-gpt

These coverage reports can also be generated locally using:
```bash
make test
```

**Additional context**
The goal is to add more test cases for the following folders. You may use the original repo's test cases as references.
- kan_gpt/
- kan_gpt/kan https://github.com/KindXiaoming/pykan
- kan_gpt/mingpt https://github.com/karpathy/minGPT
- kan_gpt/efficient_kan https://github.com/Blealtan/efficient-kan

This is a great starter issue for anyone interested in sinking their teeth deep into the repo :)