Use the named commits in the tests so that they will still refer to the
same commit if the setup gets changed in the future whereas 'branch~2'
will change which commit it points to.
Mentored-by: Christian Couder <chriscool@tuxfamily.org> Mentored-by: Phillip Wood <phillip.wood@dunelm.org.uk> Helped-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Charvi Mendiratta <charvi077@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>