Tests with puppet_facts

@raphink I can't figure out with this is not working...
interesting, I don't have the same error on my own machine:
```
$ bundle exec rake spec SPEC_OPTS="-fd" SPEC=spec/classes/openldap_server_spec.rb
/usr/bin/ruby2.1 -S rspec spec/classes/openldap_server_spec.rb --color
augeasproviders: setting Puppet[:libdir] to work around broken type autoloading
~/vendor/bundle/ruby/2.1.0/gems/puppet-3.7.3/lib/semver.rb:71:in `initialize': Invalid version string 'PE2.8.0'! (ArgumentError)
	from ~/vendor/bundle/ruby/2.1.0/bundler/gems/puppet_facts-b4ca93466cfd/lib/puppet_facts.rb:75:in `new'
...
```