belongs_to_with_deleted should pass scope to belongs_to_without_deleted

From Rails 4, [`#belongs_to` method take 3 arguments](https://github.com/rails/rails/blob/a1bb6c8b06db83546179175b9b2dde7912c86f9b/activerecord/lib/active_record/associations.rb#L1396-L1398):

```ruby
# activerecord/lib/active_record/associations.rb:1396
def belongs_to(name, scope = nil, options = {})
  Builder::BelongsTo.build(self, name, scope, options)
end
```

So `#belongs_to_with_deleted` method should also take `scope` argument nad pass it to `#belongs_to_without_deleted` method.

Without this implementation, we will get `NoMethodError` when `scope` is given like this:

```ruby
belongs_to :product, -> { includes(:manufacturer) }
# lib/acts_as_paranoid/associations.rb:12:in `belongs_to_with_deleted': undefined method `delete' for #<Proc:0x000000058fbba0> (NoMethodError)
```

Also, I think you should merge this PR before goncalossilva/rails3_acts_as_paranoid/pull/102 is merged.