To test the color output, we must convince "git branch" to
write colors to a non-terminal. We do that now by setting
the color config to "always". In preparation for the
behavior of "always" changing, let's switch to using the
"--color" command-line option, which is more direct.
Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>