test/starky: make ps_file and s3_creds params optional
test/starky: make ps_file and s3_creds params optional

Run relevant tests depending on which parameters were supplied, if any.

Signed-off-by: David Disseldorp <589a549dc9f982d9f46aeeb82a09ab6d87ccf1d8@suse.de>

ddiss/elasto,ddiss/elasto