chore: issue 321 (Wrap Errors where applicable)

[ZwangaMukwevho]

Summary

This pull requests wraps the errors on the saveOpenAPIToFile(jsonSpecLocalPath string, jsonSpec []byte) for better traceability and debugging

Issue

Addresses this issue 321

[ccoVeille]

I would have updated the PR title to be more meaningful but except that I'm OK

[ZwangaMukwevho]

I would have updated the PR title to be more meaningful but except that I'm OK

Thanks for having a quick look. I've update the title as well

[dylanhitt]

Thanks for the contribution!

You may want to base on #302. If not, I can deal with the conflict later.

[EwenQuim]

Thanks a lot for your PR!