Add request tests

- At this point we have a basic controller / view / route, so the basic request tests we add for all migrated
  routes will pass.

Author: andysellick

spec/requests/html_publication_spec.rb

@@ -0,0 +1,24 @@
+RSpec.describe "HTML publication" do
+  let(:content_item) { GovukSchemas::Example.find("html_publication", example_name: "long_form_and_automatically_numbered_headings") }
+  let(:base_path) { content_item.fetch("base_path") }
+
+  before do
+    stub_content_store_has_item(base_path, content_item)
+  end
+
+  describe "GET show" do
+    context "when visiting a HTML publication page" do
+      it "returns 200" do
+        get base_path
+
+        expect(response).to have_http_status(:ok)
+      end
+
+      it "renders the show template" do
+        get base_path
+
+        expect(response).to render_template("show")
+      end
+    end
+  end
+end