test-lib.sh: convert $TEST_DIRECTORY to an absolute path
test-lib.sh: convert $TEST_DIRECTORY to an absolute path

If $TEST_DIRECTORY is specified in the environment, convert the value
to an absolute path to ensure that it remains valid even when 'cd' is
used.

Signed-off-by: Felipe Contreras <de77a8b9cd239b204c19c52ed62e48ab47243362@gmail.com>
Reviewed-by: Richard Hansen <b2eb39c2540dc27c75dc44a8dc9f96af73df0e80@bbn.com>
Signed-off-by: Richard Hansen <b2eb39c2540dc27c75dc44a8dc9f96af73df0e80@bbn.com>
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