Replace apivore with rswag for api tests (#969)

* Replace apivore api tests with rswag
* move to OpenAPI Spec 3.0.1
* a swagger UI is now reachable at http://localhost:3000/api-docs/index.html
*  swagger file is generated by running  `RAILS_ENV=test rails rswag`
    and it was moved from /docs/swagger.v1.yml to /swagger/v1/swagger.yml

---------

Co-authored-by: viehlieb <pf@pragma-shift.net>

config/routes.rb

@@ -1,4 +1,7 @@
+# rubocop:disable Metrics/BlockLength
 Rails.application.routes.draw do
+  mount Rswag::Ui::Engine => '/api-docs'
+  mount Rswag::Api::Engine => '/api-docs'
   get "order_comments/new"
 
   get "comments/new"
@@ -290,3 +293,4 @@ Rails.application.routes.draw do
     resources :users, only: [:index]
   end # End of /:foodcoop scope
 end
+# rubocop:enable Metrics/BlockLength