use 5.6.0;

Just FYI - This actually breaks in 5.10, it should be 5.006. Here is what the docs say about it.

v-string in use/require is non-portable
(W portable) The use of v-strings is non-portable to older, pre-5.6, Perls. If you want your scripts to be backward portable, use the floating point version number: for example, instead of "use 5.6.1" say "use 5.006_001". This of course won't help: the older Perls won't suddenly start understanding newer features, but at least they will show a sensible error message indicating the required minimum version.