These function are primarily for package authors, who want more
control over the user interface, so they want to avoid calling
gitcreds_get() and gitcreds_set() directly.
The standard output of the git command, line by line.
gitcreds_fill() calls git credential fill to query git
credentials.
gitcreds_approve() calls git credential approve
to add new credentials.
gitcreds_parse_output() to parse the output of
gitcreds_fill().