t0020: use test_* helpers instead of hand-rolled messages
t0020: use test_* helpers instead of hand-rolled messages

These tests are not wrong, but it is much shorter and more
idiomatic to say "verbose" or "test_must_fail" rather than
printing our own messages on failure. Likewise, there is no
need to say "happy" at the end of a test; the test suite
takes care of that.

Signed-off-by: Jeff King <696e3fbcf235d40b6ea1ebd61c87cbea79d444e7@peff.net>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git