Bump Gems, remove warnings

Gemfile

@@ -1,16 +1,16 @@
 source 'https://rubygems.org'
-ruby "~> 2.5.1"
+ruby "~> 2.7.3"
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
-gem 'rails', '5.0.1'
+gem 'rails', '5.2.6'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use SCSS for stylesheets
 gem 'sass-rails', '~> 5.0'
 # Use Uglifier as compressor for JavaScript assets
 gem 'uglifier', '>= 1.3.0'
 # Use CoffeeScript for .coffee assets and views
-gem 'coffee-rails', '~> 4.1.0'
+gem 'coffee-rails'
 # See https://github.com/rails/execjs#readme for more supported runtimes
 # gem 'therubyracer', platforms: :ruby
 
@@ -19,9 +19,9 @@ gem 'jquery-rails'
 # Turbolinks makes following links in your web application faster. Read more: https://github.com/rails/turbolinks
 gem 'turbolinks'
 # Build JSON APIs with ease. Read more: https://github.com/rails/jbuilder
-gem 'jbuilder', '~> 2.0'
+gem 'jbuilder'
 # bundle exec rake doc:rails generates the API under doc/api.
-gem 'sdoc', '~> 0.4.0', group: :doc
+gem 'sdoc', group: :doc
 
 # Use ActiveModel has_secure_password
 # gem 'bcrypt', '~> 3.1.7'
@@ -47,7 +47,7 @@ end
 
 group :production do
   gem 'rails_12factor'
-  gem 'mysql2', '~> 0.4.0'
+  gem 'mysql2'
   gem 'pg'
 end
 

Gemfile.lock

@@ -1,189 +1,192 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    actioncable (5.0.1)
-      actionpack (= 5.0.1)
-      nio4r (~> 1.2)
-      websocket-driver (~> 0.6.1)
-    actionmailer (5.0.1)
-      actionpack (= 5.0.1)
-      actionview (= 5.0.1)
-      activejob (= 5.0.1)
+    actioncable (5.2.6)
+      actionpack (= 5.2.6)
+      nio4r (~> 2.0)
+      websocket-driver (>= 0.6.1)
+    actionmailer (5.2.6)
+      actionpack (= 5.2.6)
+      actionview (= 5.2.6)
+      activejob (= 5.2.6)
       mail (~> 2.5, >= 2.5.4)
       rails-dom-testing (~> 2.0)
-    actionpack (5.0.1)
-      actionview (= 5.0.1)
-      activesupport (= 5.0.1)
-      rack (~> 2.0)
-      rack-test (~> 0.6.3)
+    actionpack (5.2.6)
+      actionview (= 5.2.6)
+      activesupport (= 5.2.6)
+      rack (~> 2.0, >= 2.0.8)
+      rack-test (>= 0.6.3)
       rails-dom-testing (~> 2.0)
       rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    actionview (5.0.1)
-      activesupport (= 5.0.1)
+    actionview (5.2.6)
+      activesupport (= 5.2.6)
       builder (~> 3.1)
-      erubis (~> 2.7.0)
+      erubi (~> 1.4)
       rails-dom-testing (~> 2.0)
-      rails-html-sanitizer (~> 1.0, >= 1.0.2)
-    activejob (5.0.1)
-      activesupport (= 5.0.1)
+      rails-html-sanitizer (~> 1.0, >= 1.0.3)
+    activejob (5.2.6)
+      activesupport (= 5.2.6)
       globalid (>= 0.3.6)
-    activemodel (5.0.1)
-      activesupport (= 5.0.1)
-    activerecord (5.0.1)
-      activemodel (= 5.0.1)
-      activesupport (= 5.0.1)
-      arel (~> 7.0)
-    activesupport (5.0.1)
+    activemodel (5.2.6)
+      activesupport (= 5.2.6)
+    activerecord (5.2.6)
+      activemodel (= 5.2.6)
+      activesupport (= 5.2.6)
+      arel (>= 9.0)
+    activestorage (5.2.6)
+      actionpack (= 5.2.6)
+      activerecord (= 5.2.6)
+      marcel (~> 1.0.0)
+    activesupport (5.2.6)
       concurrent-ruby (~> 1.0, >= 1.0.2)
-      i18n (~> 0.7)
+      i18n (>= 0.7, < 2)
       minitest (~> 5.1)
       tzinfo (~> 1.1)
-    arel (7.1.4)
-    binding_of_caller (0.8.0)
+    arel (9.0.0)
+    binding_of_caller (1.0.0)
       debug_inspector (>= 0.0.1)
-    builder (3.2.3)
-    byebug (10.0.2)
-    coffee-rails (4.1.1)
+    builder (3.2.4)
+    byebug (11.1.3)
+    coffee-rails (5.0.0)
       coffee-script (>= 2.2.0)
-      railties (>= 4.0.0, < 5.1.x)
+      railties (>= 5.2.0)
     coffee-script (2.4.1)
       coffee-script-source
       execjs
     coffee-script-source (1.12.2)
-    concurrent-ruby (1.0.5)
-    crass (1.0.4)
-    debug_inspector (0.0.3)
-    erubis (2.7.0)
-    execjs (2.7.0)
-    ffi (1.9.25)
-    globalid (0.4.1)
+    concurrent-ruby (1.1.9)
+    crass (1.0.6)
+    debug_inspector (1.1.0)
+    erubi (1.10.0)
+    execjs (2.8.1)
+    ffi (1.15.3)
+    globalid (0.4.2)
       activesupport (>= 4.2.0)
-    i18n (0.9.5)
+    i18n (1.8.10)
       concurrent-ruby (~> 1.0)
-    jbuilder (2.7.0)
-      activesupport (>= 4.2.0)
-      multi_json (>= 1.2)
-    jquery-rails (4.3.3)
+    jbuilder (2.11.2)
+      activesupport (>= 5.0.0)
+    jquery-rails (4.4.0)
       rails-dom-testing (>= 1, < 3)
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
-    json (1.8.6)
-    loofah (2.2.2)
+    loofah (2.10.0)
       crass (~> 1.0.2)
       nokogiri (>= 1.5.9)
-    mail (2.7.0)
+    mail (2.7.1)
       mini_mime (>= 0.1.1)
-    method_source (0.9.0)
-    mini_mime (1.0.1)
-    mini_portile2 (2.3.0)
-    minitest (5.11.3)
-    multi_json (1.13.1)
-    mysql2 (0.4.10)
-    nio4r (1.2.1)
-    nokogiri (1.8.4)
-      mini_portile2 (~> 2.3.0)
-    pg (1.1.3)
-    rack (2.0.5)
-    rack-test (0.6.3)
-      rack (>= 1.0)
-    rails (5.0.1)
-      actioncable (= 5.0.1)
-      actionmailer (= 5.0.1)
-      actionpack (= 5.0.1)
-      actionview (= 5.0.1)
-      activejob (= 5.0.1)
-      activemodel (= 5.0.1)
-      activerecord (= 5.0.1)
-      activesupport (= 5.0.1)
-      bundler (>= 1.3.0, < 2.0)
-      railties (= 5.0.1)
+    marcel (1.0.1)
+    method_source (1.0.0)
+    mini_mime (1.1.0)
+    mini_portile2 (2.6.1)
+    minitest (5.14.4)
+    mysql2 (0.5.3)
+    nio4r (2.5.7)
+    nokogiri (1.12.5)
+      mini_portile2 (~> 2.6.1)
+      racc (~> 1.4)
+    pg (1.2.3)
+    racc (1.5.2)
+    rack (2.2.3)
+    rack-test (1.1.0)
+      rack (>= 1.0, < 3)
+    rails (5.2.6)
+      actioncable (= 5.2.6)
+      actionmailer (= 5.2.6)
+      actionpack (= 5.2.6)
+      actionview (= 5.2.6)
+      activejob (= 5.2.6)
+      activemodel (= 5.2.6)
+      activerecord (= 5.2.6)
+      activestorage (= 5.2.6)
+      activesupport (= 5.2.6)
+      bundler (>= 1.3.0)
+      railties (= 5.2.6)
       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)
+    rails-html-sanitizer (1.3.0)
+      loofah (~> 2.3)
     rails_12factor (0.0.3)
       rails_serve_static_assets
       rails_stdout_logging
     rails_serve_static_assets (0.0.5)
     rails_stdout_logging (0.0.5)
-    railties (5.0.1)
-      actionpack (= 5.0.1)
-      activesupport (= 5.0.1)
+    railties (5.2.6)
+      actionpack (= 5.2.6)
+      activesupport (= 5.2.6)
       method_source
       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)
-    rdoc (4.3.0)
-    sass (3.5.7)
+      thor (>= 0.19.0, < 2.0)
+    rake (13.0.3)
+    rb-fsevent (0.11.0)
+    rb-inotify (0.10.1)
+      ffi (~> 1.0)
+    rdoc (6.3.2)
+    sass (3.7.4)
       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-rails (5.1.0)
+      railties (>= 5.2.0)
       sass (~> 3.1)
       sprockets (>= 2.8, < 4.0)
       sprockets-rails (>= 2.0, < 4.0)
       tilt (>= 1.1, < 3)
-    sdoc (0.4.2)
-      json (~> 1.7, >= 1.7.7)
-      rdoc (~> 4.0)
-    spring (2.0.2)
-      activesupport (>= 4.2)
+    sdoc (2.2.0)
+      rdoc (>= 5.0)
+    spring (2.1.1)
     sprockets (3.7.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (3.2.1)
+    sprockets-rails (3.2.2)
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)
-    sqlite3 (1.3.13)
-    thor (0.20.0)
+    sqlite3 (1.4.2)
+    thor (1.1.0)
     thread_safe (0.3.6)
-    tilt (2.0.8)
-    turbolinks (5.2.0)
+    tilt (2.0.10)
+    turbolinks (5.2.1)
       turbolinks-source (~> 5.2)
     turbolinks-source (5.2.0)
-    tzinfo (1.2.5)
+    tzinfo (1.2.9)
       thread_safe (~> 0.1)
-    uglifier (4.1.18)
+    uglifier (4.2.0)
       execjs (>= 0.3.0, < 3)
     web-console (2.3.0)
       activemodel (>= 4.0)
       binding_of_caller (>= 0.7.2)
       railties (>= 4.0)
       sprockets-rails (>= 2.0, < 4.0)
-    websocket-driver (0.6.5)
+    websocket-driver (0.7.5)
       websocket-extensions (>= 0.1.0)
-    websocket-extensions (0.1.3)
+    websocket-extensions (0.1.5)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
   byebug
-  coffee-rails (~> 4.1.0)
-  jbuilder (~> 2.0)
+  coffee-rails
+  jbuilder
   jquery-rails
-  mysql2 (~> 0.4.0)
+  mysql2
   pg
-  rails (= 5.0.1)
+  rails (= 5.2.6)
   rails_12factor
   sass-rails (~> 5.0)
-  sdoc (~> 0.4.0)
+  sdoc
   spring
   sqlite3
   turbolinks
   uglifier (>= 1.3.0)
   web-console (~> 2.0)
 
 RUBY VERSION
-   ruby 2.5.1p57
+   ruby 2.7.3p183
 
 BUNDLED WITH
-   1.16.4
+   2.2.21

app/views/partials/_header.html.erb

@@ -5,7 +5,7 @@
       <%= image_tag 'the-rabbit.svg', width: 52, class: 'txt-m', alt: 'Cloud Foundry', title: 'Cloud Foundry' %>
     <% end %>
     <span class='h1 em-high txt-m mhl type-neutral-4'>+</span>
-    <%= link_to 'https://ruby-lang.org', target: '_blank' do %>
+    <%= link_to 'https://www.ruby-lang.org', target: '_blank' do %>
       <%= image_tag 'ruby_logo.svg', width: 46, class: 'txt-m', alt: 'Ruby', title: 'Ruby' %>
     <% end %>
   </div>

config/application.rb

@@ -20,7 +20,5 @@ class Application < Rails::Application
     # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
     # config.i18n.default_locale = :de
 
-    # Do not swallow errors in after_commit/after_rollback callbacks.
-    config.active_record.raise_in_transactional_callbacks = true
   end
 end