Include DFC version in API URL

And let the OFN app decide under which name to mount the DFC engine.
It simplifies the code and will make it more flexible to introduce other
versions in the future.

config/routes/api.rb

@@ -8,7 +8,7 @@ Openfoodnetwork::Application.routes.draw do
 
     constraints FeatureToggleConstraint.new(:dfc_provider) do
       # Mount DFC API endpoints
-      mount DfcProvider::Engine, at: '/'
+      mount DfcProvider::Engine, at: '/dfc-v1.6/'
     end
 
     namespace :v0 do

engines/dfc_provider/app/serializers/dfc_provider/catalog_item_serializer.rb

@@ -14,7 +14,7 @@ module DfcProvider
              key: 'dfc:offeredThrough'
 
     def id
-      dfc_provider_routes.dfc_provider_enterprise_catalog_item_url(
+      dfc_provider_routes.enterprise_catalog_item_url(
         enterprise_id: object.product.supplier_id,
         id: object.id,
         host: host
@@ -41,7 +41,7 @@ module DfcProvider
     private
 
     def reference_id
-      dfc_provider_routes.dfc_provider_enterprise_supplied_product_url(
+      dfc_provider_routes.enterprise_supplied_product_url(
         enterprise_id: object.product.supplier_id,
         id: object.id,
         host: host

engines/dfc_provider/app/serializers/dfc_provider/enterprise_serializer.rb

@@ -16,7 +16,7 @@ module DfcProvider
              serializer: DfcProvider::CatalogItemSerializer
 
     def id
-      dfc_provider_routes.dfc_provider_enterprise_url(
+      dfc_provider_routes.enterprise_url(
         id: object.id,
         host: host
       )

engines/dfc_provider/app/serializers/dfc_provider/person_serializer.rb

@@ -26,7 +26,7 @@ module DfcProvider
     end
 
     def id
-      dfc_provider_routes.dfc_provider_person_url(
+      dfc_provider_routes.person_url(
         id: object.id,
         host: host
       )

engines/dfc_provider/app/serializers/dfc_provider/supplied_product_serializer.rb

@@ -17,7 +17,7 @@ module DfcProvider
     has_many :physical_characteristics, key: 'dfc:physicalCharacterisctics'
 
     def id
-      dfc_provider_routes.dfc_provider_enterprise_supplied_product_url(
+      dfc_provider_routes.enterprise_supplied_product_url(
         enterprise_id: object.product.supplier_id,
         id: object.id,
         host: host

engines/dfc_provider/config/routes.rb

@@ -1,11 +1,9 @@
 # frozen_string_literal: true
 
 DfcProvider::Engine.routes.draw do
-  scope :dfc_provider, as: :dfc_provider, path: '/dfc_provider' do
-    resources :enterprises, only: [:show] do
-      resources :catalog_items, only: [:index, :show]
-      resources :supplied_products, only: [:show]
-    end
-    resources :persons, only: [:show]
+  resources :enterprises, only: [:show] do
+    resources :catalog_items, only: [:index, :show]
+    resources :supplied_products, only: [:show]
   end
+  resources :persons, only: [:show]
 end

engines/dfc_provider/spec/serializers/dfc_provider/catalog_item_serializer_spec.rb

@@ -11,12 +11,11 @@ describe DfcProvider::CatalogItemSerializer do
   describe '#id' do
     let(:catalog_item_id) {
       [
-        'http://test.host/api/dfc_provider',
-        'enterprises',
+        "http://test.host/api/dfc-v1.6/enterprises/",
         product.supplier_id,
-        'catalog_items',
+        "/catalog_items/",
         variant.id
-      ].join('/')
+      ].join
     }
 
     it 'returns the expected value' do
@@ -27,12 +26,11 @@ describe DfcProvider::CatalogItemSerializer do
   describe '#references' do
     let(:supplied_product_id) {
       [
-        'http://test.host/api/dfc_provider',
-        'enterprises',
+        "http://test.host/api/dfc-v1.6/enterprises/",
         product.supplier_id,
-        'supplied_products',
+        "/supplied_products/",
         variant.id
-      ].join('/')
+      ].join
     }
 
     it 'returns the expected value' do

engines/dfc_provider/spec/serializers/dfc_provider/supplied_product_serializer_spec.rb

@@ -11,12 +11,11 @@ describe DfcProvider::SuppliedProductSerializer do
   describe '#id' do
     let(:supplied_product_id) {
       [
-        'http://test.host/api/dfc_provider',
-        'enterprises',
+        "http://test.host/api/dfc-v1.6/enterprises/",
         product.supplier_id,
-        'supplied_products',
+        "/supplied_products/",
         variant.id
-      ].join('/')
+      ].join
     }
 
     it 'returns the expected value' do