(rspec) Nfs: Fix puppet-module-nfs sha

* The previous commit broke rspec tests.
* Refs: #717 #725
* See: https://github.com/enovance/puppet-module-nfs/commit/eced57eeedc55e30e8e1dd18332e192855f5f396
Merge pull request #726 from enovance/fix-rspec

(rspec) Nfs: Fix puppet-module-nfs sha
Advanced Firewalling feature

This patch enables Firewalling in this Puppet modules in a flexible way.

* Enable firewalling optionnaly (disabled by default).
* Enable 'pre' firewalling with defaults rules.
* Enable 'post' firewalling with DROP rule, with a debug option to
  disable it.
* Enable default rules for all services (OpenStack, etc).
* Ability to add custom firewall rules with Hiera
* Update puppetlabs-firewall refs
* Refactorize unit-tests