First of all, let me introduce the rationale of working on this git-fix-whitespace project. Most of the time, as a Python developer, I hate tab indentation and trailing whitespaces (read pep8). I know there are existing tools to "proof-read" a file using certain whitespacing rules. However, I insist to create my own tool to achieve the goal. Reason: I just wanna have a pet project that I LOVE to keep working on.
The very first requirement of this project is to support the configuration directives of git (see `man git-config` and look for `core.whitespace`). Hence, I need to find a tool that can read the git configuration files (both the user level git config file ~/.gitconfig and repository level git config file