Let's leave the demo app on rails 4

Author: chris-hut

Gemfile

@@ -4,5 +4,7 @@ gemspec
 gem 'pg', platform: :ruby
 gem 'activerecord-jdbcpostgresql-adapter', platform: :jruby
 
-gem "rails", "~> 5.2"
-gem "sass-rails", "~> 5.0"
+gem 'jquery-rails'
+
+gem 'rails', '~> 4.0.12'
+gem 'sass-rails', '~> 4.0.5'

Gemfile.lock

@@ -11,118 +11,71 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    actioncable (5.2.0)
-      actionpack (= 5.2.0)
-      nio4r (~> 2.0)
-      websocket-driver (>= 0.6.1)
-    actionmailer (5.2.0)
-      actionpack (= 5.2.0)
-      actionview (= 5.2.0)
-      activejob (= 5.2.0)
+    actionmailer (4.0.13)
+      actionpack (= 4.0.13)
       mail (~> 2.5, >= 2.5.4)
-      rails-dom-testing (~> 2.0)
-    actionpack (5.2.0)
-      actionview (= 5.2.0)
-      activesupport (= 5.2.0)
-      rack (~> 2.0)
-      rack-test (>= 0.6.3)
-      rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (5.2.0)
-      activesupport (= 5.2.0)
-      builder (~> 3.1)
-      erubi (~> 1.4)
-      rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.0, >= 1.0.3)
-    activejob (5.2.0)
-      activesupport (= 5.2.0)
-      globalid (>= 0.3.6)
-    activemodel (5.2.0)
-      activesupport (= 5.2.0)
-    activerecord (5.2.0)
-      activemodel (= 5.2.0)
-      activesupport (= 5.2.0)
-      arel (>= 9.0)
-    activestorage (5.2.0)
-      actionpack (= 5.2.0)
-      activerecord (= 5.2.0)
-      marcel (~> 0.3.1)
-    activesupport (5.2.0)
-      concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (>= 0.7, < 2)
-      minitest (~> 5.1)
-      tzinfo (~> 1.1)
-    arel (9.0.0)
-    builder (3.2.3)
+    actionpack (4.0.13)
+      activesupport (= 4.0.13)
+      builder (~> 3.1.0)
+      erubis (~> 2.7.0)
+      rack (~> 1.5.2)
+      rack-test (~> 0.6.2)
+    activemodel (4.0.13)
+      activesupport (= 4.0.13)
+      builder (~> 3.1.0)
+    activerecord (4.0.13)
+      activemodel (= 4.0.13)
+      activerecord-deprecated_finders (~> 1.0.2)
+      activesupport (= 4.0.13)
+      arel (~> 4.0.0)
+    activerecord-deprecated_finders (1.0.4)
+    activesupport (4.0.13)
+      i18n (~> 0.6, >= 0.6.9)
+      minitest (~> 4.2)
+      multi_json (~> 1.3)
+      thread_safe (~> 0.1)
+      tzinfo (~> 0.3.37)
+    arel (4.0.2)
+    builder (3.1.4)
     coffee-rails (4.2.2)
       coffee-script (>= 2.2.0)
       railties (>= 4.0.0)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.0.5)
-    crass (1.0.4)
     diff-lcs (1.2.5)
-    erubi (1.7.1)
+    erubis (2.7.0)
     execjs (2.7.0)
-    ffi (1.9.25)
-    globalid (0.4.1)
-      activesupport (>= 4.2.0)
-    i18n (1.0.1)
-      concurrent-ruby (~> 1.0)
+    hike (1.2.3)
+    i18n (0.7.0)
     ice_cube (0.16.2)
-    jquery-rails (4.3.3)
-      rails-dom-testing (>= 1, < 3)
-      railties (>= 4.2.0)
+    jquery-rails (3.1.2)
+      railties (>= 3.0, < 5.0)
       thor (>= 0.14, < 2.0)
-    loofah (2.2.2)
-      crass (~> 1.0.2)
-      nokogiri (>= 1.5.9)
-    mail (2.7.0)
-      mini_mime (>= 0.1.1)
-    marcel (0.3.2)
-      mimemagic (~> 0.3.2)
-    method_source (0.9.0)
-    mimemagic (0.3.2)
-    mini_mime (1.0.0)
-    mini_portile2 (2.3.0)
-    minitest (5.11.3)
-    nio4r (2.3.1)
-    nokogiri (1.8.4)
-      mini_portile2 (~> 2.3.0)
+    mail (2.6.3)
+      mime-types (>= 1.16, < 3)
+    mime-types (2.6.2)
+    minitest (4.7.5)
+    multi_json (1.11.2)
     pg (0.17.1)
-    rack (2.0.5)
-    rack-test (1.0.0)
-      rack (>= 1.0, < 3)
-    rails (5.2.0)
-      actioncable (= 5.2.0)
-      actionmailer (= 5.2.0)
-      actionpack (= 5.2.0)
-      actionview (= 5.2.0)
-      activejob (= 5.2.0)
-      activemodel (= 5.2.0)
-      activerecord (= 5.2.0)
-      activestorage (= 5.2.0)
-      activesupport (= 5.2.0)
-      bundler (>= 1.3.0)
-      railties (= 5.2.0)
-      sprockets-rails (>= 2.0.0)
-    rails-dom-testing (2.0.3)
-      activesupport (>= 4.2.0)
-      nokogiri (>= 1.6)
-    rails-html-sanitizer (1.0.4)
-      loofah (~> 2.2, >= 2.2.2)
-    railties (5.2.0)
-      actionpack (= 5.2.0)
-      activesupport (= 5.2.0)
-      method_source
+    rack (1.5.5)
+    rack-test (0.6.3)
+      rack (>= 1.0)
+    rails (4.0.13)
+      actionmailer (= 4.0.13)
+      actionpack (= 4.0.13)
+      activerecord (= 4.0.13)
+      activesupport (= 4.0.13)
+      bundler (>= 1.3.0, < 2.0)
+      railties (= 4.0.13)
+      sprockets-rails (~> 2.0)
+    railties (4.0.13)
+      actionpack (= 4.0.13)
+      activesupport (= 4.0.13)
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
-    rake (12.3.1)
-    rb-fsevent (0.10.3)
-    rb-inotify (0.9.10)
-      ffi (>= 0.5.0, < 2)
+    rake (10.4.2)
     rspec (3.1.0)
       rspec-core (~> 3.1.0)
       rspec-expectations (~> 3.1.0)
@@ -143,46 +96,40 @@ GEM
       rspec-mocks (~> 3.1.0)
       rspec-support (~> 3.1.0)
     rspec-support (3.1.2)
-    sass (3.5.7)
-      sass-listen (~> 4.0.0)
-    sass-listen (4.0.0)
-      rb-fsevent (~> 0.9, >= 0.9.4)
-      rb-inotify (~> 0.9, >= 0.9.7)
-    sass-rails (5.0.7)
-      railties (>= 4.0.0, < 6)
-      sass (~> 3.1)
+    sass (3.2.19)
+    sass-rails (4.0.5)
+      railties (>= 4.0.0, < 5.0)
+      sass (~> 3.2.2)
+      sprockets (~> 2.8, < 3.0)
+      sprockets-rails (~> 2.0)
+    sprockets (2.12.4)
+      hike (~> 1.2)
+      multi_json (~> 1.0)
+      rack (~> 1.0)
+      tilt (~> 1.1, != 1.3.0)
+    sprockets-rails (2.3.3)
+      actionpack (>= 3.0)
+      activesupport (>= 3.0)
       sprockets (>= 2.8, < 4.0)
-      sprockets-rails (>= 2.0, < 4.0)
-      tilt (>= 1.1, < 3)
-    sprockets (3.7.2)
-      concurrent-ruby (~> 1.0)
-      rack (> 1, < 3)
-    sprockets-rails (3.2.1)
-      actionpack (>= 4.0)
-      activesupport (>= 4.0)
-      sprockets (>= 3.0.0)
-    thor (0.20.0)
-    thread_safe (0.3.6)
-    tilt (2.0.8)
-    tzinfo (1.2.5)
-      thread_safe (~> 0.1)
-    websocket-driver (0.7.0)
-      websocket-extensions (>= 0.1.0)
-    websocket-extensions (0.1.3)
+    thor (0.19.1)
+    thread_safe (0.3.5)
+    tilt (1.4.1)
+    tzinfo (0.3.44)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   activerecord-jdbcpostgresql-adapter
   bundler (>= 1.3.5)
+  jquery-rails
   pg
-  rails (~> 5.2)
+  rails (~> 4.0.12)
   rake (>= 0.9.6)
   recurring_select!
   rspec (>= 2.14)
   rspec-rails (>= 2.14)
-  sass-rails (~> 5.0)
+  sass-rails (~> 4.0.5)
 
 BUNDLED WITH
    1.16.2