FactorialTest

[7IronSnow7]

• [x ] I have performed a self-review of my code
• [x] My code follows the style guidelines of this project
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes
• [x] Comments in areas I changed are up to date
• [x] I have added comments to hard-to-understand areas of my code
• [x] I have made corresponding changes to the README.md

[siriak]

This is not a unit test, see examples of other tests in the repository