Add empty SDG index

spec/controllers/sdg/goals_spec.rb

@@ -0,0 +1,13 @@
+require 'rails_helper'
+
+describe SDG::GoalsController do
+  context "featured disabled" do
+    before do
+      Setting["feature.sdg"] = false
+    end
+
+    it "raises feature disabled" do
+      expect { get :index }.to raise_exception(FeatureFlags::FeatureDisabled)
+    end
+  end
+end