Add option to backup existing files

[artivis]

Description

Add an option to backup existing file before removing them. This creates a copy of an existing foo.yaml file to foo.yaml.bk.

Related Issue

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)
• [ ] Chore (non-breaking change that does not add functionality or fix an issue)

Checklist:

• [ ] I have read the CONTRIBUTING document.
• [ ] I have run the pre-merge tests locally and they pass.
• [ ] I have updated the documentation accordingly.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.