t7510: test verify-commit
This mixes the "git verify-commit" tests in with the "git show
--show-signature" tests, to keep the tests more readable.
The tests already mix in the "call show" tests with the "verify" tests.
So in case of a test beakage, a '-v' run would be needed to reveal the
exact point of breakage anyway.
Additionally, test the actual output of "git verify-commit" and "git
show --show-signature" and compare to "git cat-file".
Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>