tests: add valgrind option to collie

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
collie: optimize vdi iteration

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
tests: print elapsed time

Signed-off-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>