Enable usage of puppetlabs-stdlib 5.x.x
Enable usage of puppetlabs-stdlib 5.x.x

This patch enables using the puppetlabs-stdlib module version 5.
Fixes https://github.com/camptocamp/puppet-openldap/issues/237
As there are no breaking changes in version 5.x that affect this
module, running these versions is fine.
https://github.com/puppetlabs/puppetlabs-stdlib/blob/master/CHANGELOG.md

nfrance-conseil/puppet-openldap,camptocamp/puppet-openldap