Function reword_root_commit 

pub fn reword_root_commit<'a>(
    repo: &'a Repository,
    old: &str,
    new: &str,
    message: &str,
) -> GitResult<Branch<'a>>

Reword the root commit of the old branch and create a new branch

Arguments

• repo: The git repository
• message: The initial commit message
• old: The old branch name
• new: The new branch name