Fixes issue #168 - VMware ESXi vSAN Model

Copied existing VMware model folder `5` and created `5_vsan`.  Modified the `kickstart.erb` file including python code from [ESXi 5.5 Kickstart script for setting up VSAN](http://www.virtuallyghetto.com/2014/07/esxi-5-5-kickstart-script-for-setting-up-vsan.html) modifing as needed for Hanlon.  Modified the `vnware_esxi.rb` to include the vSAN uuid optional parameter
```
"@vsan_uuid"            => { :default     => "",
                                            :example     => "aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee",
                                            :validation  => '^[a-z\d]{8}-[a-z\d]{4}-[a-z\d]{4}-[a-z\d]{4}-[a-z\d]{12}$',
                                            :required    => false,
                                            :description => "Optional for vSAN use: if first vSAN node leave empty" },
```

This has been tested in a nested environment with three total hosts.  When each host is added the free space of the vSAN datastore increases correspondingly.