fix(test): don't use hardcoded tmp directory

[codymikol]

This PR contains a:

• [x] bugfix
• [ ] new feature
• [ ] code refactor
• [ ] test update
• [ ] typo fix
• [ ] metadata update

Motivation / Use-Case

as it turns out os.tmpdir() is a function for a reason :p. this changes the test to NOT use the hardcoded tmp dir, but instead just use os.tmpdir so that tests under other OSs will still pass.

Fixes N/A

Breaking Changes

N/A

Additional Info

N/A