Added prefix option to router.

[AlfonsoUceda]

Problem

There is a problem in lotusrb gem generating correct routes when the apps are mounted inside lotus container:

class AdminApp  < Lotus::Application
  configure do
    routes do
      get '/home', to 'home#index', as: :home
    end
  end
end
Lotus::Container.configure do
  mount AdminApp, at: '/admin'
  mount App, at: '/'
end
AdminApp::Routes.path(:home) # => '/home' <- WRONG
# should be
AdminApp::Routes.path(:home) # => '/admin/home' <- GOOD

Solution

This PR add prefix option to router, later we can pass in lotusrb the at: option as prefix for the router.

router = Lotus::Router.new(prefix: '/admin') do
  get '/home', to: 'home#index', as: ':home'
end

router.path(:home) # => '/admin/home'

[jodosha]

@AlfonsoUceda This leaks Lotus::Routing::HttpRouter details to the higher level. That low level class should hide this detail. Lotus::Router#get should remain untouched, while Lotus::Routing::HttpRouter#get should handle this.

[jodosha]

@AlfonsoUceda This looks really, really clean now 👏