This commit fixes the selinux-reference for the newest version

The voxpupuli-selinux module changed from "source" to "source_te"
for .te files. Fixed that in this PR, also upped the version in
the metadata.json and .fixtures.yml. Also for puppetlabs-stdlib,
since this module is Puppet 4 only the stdlib needs to be at least
4.6.0 according to the README of the stdlib-module.