Added plate_purposes controller

app/controllers/api/v2/plate_purposes_controller.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module Api
+  module V2
+    # Provides a JSON API controller for receptacle
+    # See: http://jsonapi-resources.com/ for JSONAPI::Resource documentation
+    class PlatePurposesController < JSONAPI::ResourceController
+      # By default JSONAPI::ResourceController provides most the standard
+      # behaviour, and in many cases this file may be left empty.
+    end
+  end
+end