Increase Test Coverage

[AdityaNG]

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

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:

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 :)