Clean up Rubocop suggestions.

Gemfile

@@ -1,10 +1,12 @@
-source "https://rubygems.org"
+# frozen_string_literal: true
+
+source 'https://rubygems.org'
 
-gem "roda"
 gem 'rake'
+gem 'roda'
 
 # change to gunicorn or passenger if you prefer:
-gem "puma"
+gem 'puma'
 
 group :development do
   gem 'rerun'

Rakefile

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'rake/testtask'
 
 Rake::TestTask.new do |task|

app.rb

@@ -1,16 +1,16 @@
 # frozen_string_literal: true
-require "roda"
 
+require 'roda'
+
+# A simple Roda app all in one file.
 class App < Roda
   route do |r|
-
     r.root do
-      "My Homepage"
+      'My Homepage'
     end
 
     r.get 'about' do
-      "About This Site"
-    end
-
+      'About This Site'
+    end
   end
 end

app_test.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'minitest/autorun'
 require 'capybara/minitest'
 
@@ -5,6 +7,7 @@ require_relative 'app'
 
 Capybara.app = App
 
+# Run tests for my simple Roda app.
 class AppTest < Minitest::Test
   include Capybara::DSL
   include Capybara::Minitest::Assertions
@@ -33,13 +36,12 @@ class  AppTest < Minitest::Test
   # Can change the checked content as your site evolves:
   def test_home_page_has_content
     visit '/'
-    assert_content "My Homepage"
+    assert_content 'My Homepage'
   end
 
   def test_about_page_exists_and_has_content
     visit '/about'
     assert_equal 200, page.status_code
-    assert_content "About This Site"
+    assert_content 'About This Site'
   end
-
 end

config.ru

@@ -1,3 +1,5 @@
-require "./app"
+# frozen_string_literal: true
+
+require './app'
 
 run App.freeze.app