Clone repository labels

[codenameyau]

This CLI should be able to clone a repository label into another repository. Add a flag to wipe out labels before adding new ones. Consider shortening this command to 2-3 characters.

github-label <source-repo> <target-repo> -r -y

# Flag to remove existing labels.
-r --replace 

# Flag to autoconfirm.
-y --yes

Before running this command this will show a prompt to ask users to confirm their changes.