test.c does not need its own directory

Signed-off-by: Mattias Andrée <maandree@operamail.com>
m improvement: make msg in libkeccak_digest const

Signed-off-by: Mattias Andrée <maandree@operamail.com>
update the test for the last commit

Signed-off-by: Mattias Andrée <maandree@operamail.com>