Create remote_directory resource

Add [remote_directory resource](https://docs.chef.io/resource_remote_directory.html) for itamae.
This is implemented with specinfra's send_directory command https://github.com/serverspec/specinfra/pull/283.

Sending some grouped files by `remote_file` is boring, so this resource is useful in such a case.
I think this is a basic resource, but I'll close this PR and gemify it if it is not suitable as built-in resource.

## example

```rb
remote_directory '/foo/bar/baz' do
  source 'hoge'
  owner  'root'
  group  'root'
  mode   '755'
  action :create
end
```