Add localhost_aliases

I try define aliases for 127.0.0.1 in this way:
```ruby
:hosts_file => {
  :custom_entries => {
    '127.0.0.1' => 'www.google.com'
  }
}
```

But this did't work, so I added `localhost_aliases` attribute. Now to add aliases for 127.0.0.1 need to do:
```ruby
:hosts_file => {
  :custom_entries => {
    :localhost_aliases => %w(www.google.com)
  }
}
```