update_authors.t - fixup shallow clone guards

We were not testing for errors from rev-parse, and we were improperly
passsing in a range and the --verify mode does not expect a range,
it expects a specific commit.

This changes the test to check each end of the commit range, and to
check for errors. It also uses the {commit} notation to check if the
objects actually are commits.

0 files changed, 0 insertions, 0 deletions