Fix for hash randomization

Hash randomization is introduced at Perl 5.18.0. (key, value) order is
changed at each execution. We should not expect (key, value) order.
Remove taint mode flag for suppressing warnings
Merge pull request #20 from syohex/fix-for-perl-5.18

Fix for hash randomization
Merge pull request #21 from syohex/remove-taint-mode

Remove taint mode flag for suppressing warnings