add check rule to the makefile

Signed-off-by: Mattias Andrée <maandree@operamail.com>
add test for libkeccak_update

Signed-off-by: Mattias Andrée <maandree@operamail.com>
prepare check rule for the test reading the license file

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