Fix tests and address #36

[ewu63]

Purpose

This PR does two things:

• Update the tests
  • moved them to outside the project directory so they are not installed
  • improved directory handling for the temporary directories used in testing
• Closes Better handling of pdflatex compilation failure #36 by invoking subprocess.run instead of os.system

Type of change

What types of change is it?
Select the appropriate type(s) that describe this PR

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (non-backwards-compatible fix or feature)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Documentation update
• Maintenance update
• Other (please describe)

Testing

Existing tests pass.

Checklist

Put an x in the boxes that apply.

• I have run flake8 and black to make sure the code adheres to PEP-8 and is consistently formatted
• I have run unit and regression tests which pass locally with my changes
• I have added new tests that prove my fix is effective or that my feature works
• I have added necessary documentation

[marcomangano]

Why did you give up with GA?

[marcomangano]

Anyway, the tests work fine and the change are definitely an improvement, thanks for taking care of this!

[ewu63]

After some discussions with @bernardopacini we decided it was best to do this on Azure to reduce code duplication.