require at least Perl 5.6

The core modules and pragmas being used require at least Perl 5.6 in
order to work. Explicitly saying "use 5.006" will make the error more
clear.

1 files changed, 1 insertions, 0 deletions

diff --git a/runtests.pl b/runtests.pl
index ce72931..7bffe81 100644
--- a/runtests.pl
+++ b/runtests.pl
@@ -1,4 +1,5 @@
 #!/usr/bin/env perl
+use 5.006;
 use warnings;
 use strict;
 use utf8;