Relax stdlib version dependency to >= 3.0

The strict dependency on 4.x meant that the module could not co-exist with
any other modules that already depend on 3.x

Strictly we don't need 4.x - it would just be nice to have the ability to
refresh anchor patterns. stdlib 3.x means that we can still support Puppet
3.x, but also Puppet 2.7 if necessary.

Per the same commit in gds-operations/puppet-module-skeleton@fe557b8
Release version 0.0.3

With relaxed stdlib dependency.