For devs, ensure `pytest` can be called from CLI on Windows

**Motivation**
There seems to be an issue relating to text encodings when calling `pytest` as a Windows dev:
> `UnicodeEncodeError: 'charmap' codec can't encode character '\u2714' in position
0: character maps to <undefined>`

This doesn't occur when using the VS Code UI.

**Summary of desired feature**
Ensure `pytest` can be called from CLI without errors.
