[t] Add a basic test for a passing exit code
[t] Add a basic test for a passing exit code

Trying to debug this:

(kadath)(~/git/tapir master )$ ~/svn/parrot/parrot t/harness.pir t/*.t
t/00-sanity.t ................. failed 0/0 tests, exit code = 1
t/01-parse_plan.t ............. failed 0/0 tests, exit code = 1
t/02-parse_tapstream.t ........ failed 0/0 tests, exit code = 1
t/03-parse_tapstream_error.t .. failed 0/0 tests, exit code = 1
FAILED 4 test(s) in 4/4 files

leto/tapir