Update the JSON API endpoint to /authors for Author.

test/decentralised_book_index/sync/api_clients/fetch_json_test.exs

@@ -11,7 +11,7 @@ defmodule DecentralisedBookIndex.Sync.ApiClients.FetchJsonTest do
     test "get an author" do
       {:ok, author} = Metadata.create_author("Author", "An description")
 
-      assert {:ok, data} = FetchJson.get("#{@test_server_endpoint}/api/v1/json/author/#{author.id}")
+      assert {:ok, data} = FetchJson.get("#{@test_server_endpoint}/api/v1/json/authors/#{author.id}")
       assert data["data"]["id"] == author.id
     end
   end

test/decentralised_book_index/sync/api_clients/fetch_jsons_test.exs

@@ -14,7 +14,7 @@ defmodule DecentralisedBookIndex.Sync.ApiClients.FetchJsonsTest do
         Metadata.create_author!("Author#{number}", "An description#{number}")
       end
 
-      assert {:ok, records} = FetchJsons.get("#{@test_server_endpoint}/api/v1/json/author")
+      assert {:ok, records} = FetchJsons.get("#{@test_server_endpoint}/api/v1/json/authors")
       assert length(records) == 11
     end
 
@@ -28,7 +28,7 @@ defmodule DecentralisedBookIndex.Sync.ApiClients.FetchJsonsTest do
       end
 
       assert {:ok, records} =
-        FetchJsons.get("#{@test_server_endpoint}/api/v1/json/author", get_author_names)
+        FetchJsons.get("#{@test_server_endpoint}/api/v1/json/authors", get_author_names)
 
       assert length(records) == 11
       assert Enum.all?(records, fn author -> String.contains?(author, "Author") end)