fix: a small bug in code coverage CLI helper

Description

The result of running the following command python ..\sight-git\sight-cov.py -d my_project_name 506 --html in the project root directory on Windows platform produces, sometimes, an UnicodeEncodeError.

How to test it?

Try to execute the command in description (but needed data could be no more available on the server...)

Related issue(s)

Closes #81 (closed)