Add ability to pass additional options to apipie route

Hi, can we add ability to pass additional options to apipie route?
In my case I'd like to add `constraints` like:

```ruby
Test::Application.routes.draw do
  apipie constraints: DeveloperConstraint.new
end

class DeveloperConstraint
  def matches?(request)
    request.env['warden'].authenticate? && request.env['warden'].user.has_role?(:developer)
  end
end
```