diff --git a/Gemfile b/Gemfile
index 206dae3..aa9107c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,7 +2,7 @@ source 'https://rubygems.org'
 
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
-gem 'rails', '4.1.7'
+gem 'rails', '4.2.0'
 # Use sqlite3 as the database for Active Record
 gem 'sqlite3'
 # Use SCSS for stylesheets
@@ -23,6 +23,8 @@ gem 'jbuilder', '~> 2.0'
 # bundle exec rake doc:rails generates the API under doc/api.
 gem 'sdoc', '~> 0.4.0',          group: :doc
 
+gem 'web-console', '~> 2.0', group: :development
+
 # Use Coveralls for coverage documentation
 gem 'coveralls', require: false
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 5d57505..b67e1bb 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,38 +1,49 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    actionmailer (4.1.7)
-      actionpack (= 4.1.7)
-      actionview (= 4.1.7)
+    actionmailer (4.2.0)
+      actionpack (= 4.2.0)
+      actionview (= 4.2.0)
+      activejob (= 4.2.0)
       mail (~> 2.5, >= 2.5.4)
-    actionpack (4.1.7)
-      actionview (= 4.1.7)
-      activesupport (= 4.1.7)
-      rack (~> 1.5.2)
+      rails-dom-testing (~> 1.0, >= 1.0.5)
+    actionpack (4.2.0)
+      actionview (= 4.2.0)
+      activesupport (= 4.2.0)
+      rack (~> 1.6.0)
       rack-test (~> 0.6.2)
-    actionview (4.1.7)
-      activesupport (= 4.1.7)
+      rails-dom-testing (~> 1.0, >= 1.0.5)
+      rails-html-sanitizer (~> 1.0, >= 1.0.1)
+    actionview (4.2.0)
+      activesupport (= 4.2.0)
       builder (~> 3.1)
       erubis (~> 2.7.0)
-    activemodel (4.1.7)
-      activesupport (= 4.1.7)
+      rails-dom-testing (~> 1.0, >= 1.0.5)
+      rails-html-sanitizer (~> 1.0, >= 1.0.1)
+    activejob (4.2.0)
+      activesupport (= 4.2.0)
+      globalid (>= 0.3.0)
+    activemodel (4.2.0)
+      activesupport (= 4.2.0)
       builder (~> 3.1)
-    activerecord (4.1.7)
-      activemodel (= 4.1.7)
-      activesupport (= 4.1.7)
-      arel (~> 5.0.0)
-    activesupport (4.1.7)
-      i18n (~> 0.6, >= 0.6.9)
+    activerecord (4.2.0)
+      activemodel (= 4.2.0)
+      activesupport (= 4.2.0)
+      arel (~> 6.0)
+    activesupport (4.2.0)
+      i18n (~> 0.7)
       json (~> 1.7, >= 1.7.7)
       minitest (~> 5.1)
-      thread_safe (~> 0.1)
+      thread_safe (~> 0.3, >= 0.3.4)
       tzinfo (~> 1.1)
-    arel (5.0.1.20140414130214)
+    arel (6.0.0)
     autoprefixer-rails (4.0.2.1)
       execjs
     bh (1.2.0)
       actionpack
       activesupport
+    binding_of_caller (0.7.2)
+      debug_inspector (>= 0.0.1)
     bootstrap-sass (3.3.1.0)
       sass (~> 3.2)
     builder (3.2.2)
@@ -49,12 +60,15 @@ GEM
       simplecov (>= 0.7)
       term-ansicolor
       thor
+    debug_inspector (0.0.2)
     docile (1.1.5)
     erubis (2.7.0)
     execjs (2.2.2)
     ffi (1.9.6)
+    globalid (0.3.0)
+      activesupport (>= 4.1.0)
     hike (1.2.3)
-    i18n (0.6.11)
+    i18n (0.7.0)
     jbuilder (2.2.5)
       activesupport (>= 3.0.0, < 5)
       multi_json (~> 1.2)
@@ -62,33 +76,47 @@ GEM
       railties (>= 3.0, < 5.0)
       thor (>= 0.14, < 2.0)
     json (1.8.1)
+    loofah (2.0.1)
+      nokogiri (>= 1.5.9)
     mail (2.6.3)
       mime-types (>= 1.16, < 3)
     mathjax-rails (2.3.0)
       railties (>= 3.0)
     mime-types (2.4.3)
-    minitest (5.4.3)
+    mini_portile (0.6.2)
+    minitest (5.5.0)
     multi_json (1.10.1)
     netrc (0.10.2)
-    rack (1.5.2)
+    nokogiri (1.6.5)
+      mini_portile (~> 0.6.0)
+    rack (1.6.0)
     rack-test (0.6.2)
       rack (>= 1.0)
-    rails (4.1.7)
-      actionmailer (= 4.1.7)
-      actionpack (= 4.1.7)
-      actionview (= 4.1.7)
-      activemodel (= 4.1.7)
-      activerecord (= 4.1.7)
-      activesupport (= 4.1.7)
+    rails (4.2.0)
+      actionmailer (= 4.2.0)
+      actionpack (= 4.2.0)
+      actionview (= 4.2.0)
+      activejob (= 4.2.0)
+      activemodel (= 4.2.0)
+      activerecord (= 4.2.0)
+      activesupport (= 4.2.0)
       bundler (>= 1.3.0, < 2.0)
-      railties (= 4.1.7)
-      sprockets-rails (~> 2.0)
-    railties (4.1.7)
-      actionpack (= 4.1.7)
-      activesupport (= 4.1.7)
+      railties (= 4.2.0)
+      sprockets-rails
+    rails-deprecated_sanitizer (1.0.3)
+      activesupport (>= 4.2.0.alpha)
+    rails-dom-testing (1.0.5)
+      activesupport (>= 4.2.0.beta, < 5.0)
+      nokogiri (~> 1.6.0)
+      rails-deprecated_sanitizer (>= 1.0.1)
+    rails-html-sanitizer (1.0.1)
+      loofah (~> 2.0)
+    railties (4.2.0)
+      actionpack (= 4.2.0)
+      activesupport (= 4.2.0)
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
-    rake (10.4.0)
+    rake (10.4.2)
     rdoc (4.1.2)
       json (~> 1.4)
     rest-client (1.7.2)
@@ -134,6 +162,11 @@ GEM
     uglifier (2.5.3)
       execjs (>= 0.3.0)
       json (>= 1.8.0)
+    web-console (2.0.0)
+      activemodel (~> 4.0)
+      binding_of_caller (>= 0.7.2)
+      railties (~> 4.0)
+      sprockets-rails (>= 2.0, < 4.0)
     will_paginate (3.0.7)
     will_paginate-bootstrap (1.0.1)
       will_paginate (>= 3.0.3)
@@ -150,12 +183,13 @@ DEPENDENCIES
   jbuilder (~> 2.0)
   jquery-rails
   mathjax-rails
-  rails (= 4.1.7)
+  rails (= 4.2.0)
   sass-rails (~> 4.0.3)
   sdoc (~> 0.4.0)
   sqlite3
   turbolinks
   tzinfo-data
   uglifier (>= 1.3.0)
+  web-console (~> 2.0)
   will_paginate (~> 3.0.6)
   will_paginate-bootstrap
diff --git a/bin/rails b/bin/rails
index b9f8787..c9a0f38 100644
--- a/bin/rails
+++ b/bin/rails
@@ -1,4 +1,4 @@
 #!/usr/bin/env ruby.exe
-APP_PATH = File.expand_path('../../config/application',  __FILE__)
+APP_PATH = File.expand_path('../../config/application', __FILE__)
 require_relative '../config/boot'
 require 'rails/commands'
diff --git a/bin/setup b/bin/setup
new file mode 100644
index 0000000..2d041ee
--- /dev/null
+++ b/bin/setup
@@ -0,0 +1,29 @@
+#!/usr/bin/env ruby.exe
+require 'pathname'
+
+# path to your application root.
+APP_ROOT = Pathname.new File.expand_path('../../',  __FILE__)
+
+Dir.chdir APP_ROOT do
+  # This script is a starting point to setup your application.
+  # Add necessary setup steps to this file:
+
+  puts "== Installing dependencies =="
+  system "gem install bundler --conservative"
+  system "bundle check || bundle install"
+
+  # puts "\n== Copying sample files =="
+  # unless File.exist?("config/database.yml")
+  #   system "cp config/database.yml.sample config/database.yml"
+  # end
+
+  puts "\n== Preparing database =="
+  system "bin/rake db:setup"
+
+  puts "\n== Removing old logs and tempfiles =="
+  system "rm -f log/*"
+  system "rm -rf tmp/cache"
+
+  puts "\n== Restarting application server =="
+  system "touch tmp/restart.txt"
+end
diff --git a/config/application.rb b/config/application.rb
index 54b7b30..18830de 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -20,5 +20,8 @@ module Projekteuler
     config.i18n.load_path += Dir[Rails.root.join('config', 'locales', '**', '*.{rb,yml}').to_s]
     config.i18n.available_locales = :de
     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
diff --git a/config/boot.rb b/config/boot.rb
index 5e5f0c1..6b750f0 100644
--- a/config/boot.rb
+++ b/config/boot.rb
@@ -1,4 +1,3 @@
-# Set up gems listed in the Gemfile.
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
 
-require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
+require 'bundler/setup' # Set up gems listed in the Gemfile.
diff --git a/config/environments/development.rb b/config/environments/development.rb
index 13bd782..012e83e 100644
--- a/config/environments/development.rb
+++ b/config/environments/development.rb
@@ -27,6 +27,10 @@ Rails.application.configure do
   # number of complex assets.
   config.assets.debug = true
 
+  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
+  # yet still be able to expire them through the digest params.
+  config.assets.digest = true
+
   # Adds additional error checking when serving assets at runtime.
   # Checks for improperly declared sprockets dependencies.
   # Raises helpful error messages.
diff --git a/config/environments/production.rb b/config/environments/production.rb
index b93a877..5c1b32e 100644
--- a/config/environments/production.rb
+++ b/config/environments/production.rb
@@ -16,11 +16,13 @@ Rails.application.configure do
 
   # Enable Rack::Cache to put a simple HTTP cache in front of your application
   # Add `rack-cache` to your Gemfile before enabling this.
-  # For large-scale production use, consider using a caching reverse proxy like nginx, varnish or squid.
+  # For large-scale production use, consider using a caching reverse proxy like
+  # NGINX, varnish or squid.
   # config.action_dispatch.rack_cache = true
 
-  # Disable Rails's static asset server (Apache or nginx will already do this).
-  config.serve_static_assets = false
+  # Disable serving static files from the `/public` folder by default since
+  # Apache or NGINX already handles this.
+  config.serve_static_files = ENV['RAILS_SERVE_STATIC_FILES'].present?
 
   # Compress JavaScripts and CSS.
   config.assets.js_compressor = :uglifier
@@ -29,20 +31,22 @@ Rails.application.configure do
   # Do not fallback to assets pipeline if a precompiled asset is missed.
   config.assets.compile = false
 
-  # Generate digests for assets URLs.
+  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
+  # yet still be able to expire them through the digest params.
   config.assets.digest = true
 
   # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb
 
   # Specifies the header that your server uses for sending files.
-  # config.action_dispatch.x_sendfile_header = "X-Sendfile" # for apache
-  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for nginx
+  # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache
+  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX
 
   # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
   # config.force_ssl = true
 
-  # Set to :debug to see everything in the log.
-  config.log_level = :info
+  # Use the lowest log level to ensure availability of diagnostic information
+  # when problems arise.
+  config.log_level = :debug
 
   # Prepend all log lines with the following tags.
   # config.log_tags = [ :subdomain, :uuid ]
@@ -54,7 +58,7 @@ Rails.application.configure do
   # config.cache_store = :mem_cache_store
 
   # Enable serving of images, stylesheets, and JavaScripts from an asset server.
-  # config.action_controller.asset_host = "http://assets.example.com"
+  # config.action_controller.asset_host = 'http://assets.example.com'
 
   # Ignore bad email addresses and do not raise email delivery errors.
   # Set this to true and configure the email server for immediate delivery to raise delivery errors.
@@ -67,9 +71,6 @@ Rails.application.configure do
   # Send deprecation notices to registered listeners.
   config.active_support.deprecation = :notify
 
-  # Disable automatic flushing of the log to improve performance.
-  # config.autoflush_log = false
-
   # Use default logging formatter so that PID and timestamp are not suppressed.
   config.log_formatter = ::Logger::Formatter.new
 
diff --git a/config/environments/test.rb b/config/environments/test.rb
index b8485ce..cc0ebf1 100644
--- a/config/environments/test.rb
+++ b/config/environments/test.rb
@@ -12,8 +12,8 @@ Rails.application.configure do
   # preloads Rails for running tests, you may have to set it to true.
   config.eager_load = false
 
-  # Configure static asset server for tests with Cache-Control for performance.
-  config.serve_static_assets  = true
+  # Configure static file server for tests with Cache-Control for performance.
+  config.serve_static_files   = true
   config.static_cache_control = 'public, max-age=3600'
 
   # Show full error reports and disable caching.
@@ -31,6 +31,9 @@ Rails.application.configure do
   # ActionMailer::Base.deliveries array.
   config.action_mailer.delivery_method = :test
 
+  # Randomize the order test cases are executed.
+  config.active_support.test_order = :random
+
   # Print deprecation notices to the stderr.
   config.active_support.deprecation = :stderr
 
diff --git a/config/initializers/assets.rb b/config/initializers/assets.rb
index ab212d0..01ef3e6 100644
--- a/config/initializers/assets.rb
+++ b/config/initializers/assets.rb
@@ -3,6 +3,9 @@
 # Version of your assets, change this if you want to expire all your assets.
 Rails.application.config.assets.version = '1.0'
 
+# Add additional assets to the asset load path
+# Rails.application.config.assets.paths << Emoji.images_path
+
 # Precompile additional assets.
-# application.js, application.css.scss, and all non-JS/CSS in app/assets folder are already added.
+# application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
 # Rails.application.config.assets.precompile += %w( search.js )
diff --git a/config/initializers/cookies_serializer.rb b/config/initializers/cookies_serializer.rb
index 7a06a89..7f70458 100644
--- a/config/initializers/cookies_serializer.rb
+++ b/config/initializers/cookies_serializer.rb
@@ -1,3 +1,3 @@
 # Be sure to restart your server when you modify this file.
 
-Rails.application.config.action_dispatch.cookies_serializer = :json
\ No newline at end of file
+Rails.application.config.action_dispatch.cookies_serializer = :json
diff --git a/config/secrets.yml b/config/secrets.yml
index 4297ca9..6d00c3a 100644
--- a/config/secrets.yml
+++ b/config/secrets.yml
@@ -11,10 +11,10 @@
 # if you're sharing your code publicly.
 
 development:
-  secret_key_base: a606d611cb230fcdc6ac0303f10c554435bc887b57795abbad145aadfa445b3389aab91de996998246d9e1f7959211df3805a58c27a047a0a80fcfc761593520
+  secret_key_base: 6c2640a4cd5352d96caea5bfb073ec7b827ad609f5a5a99680dbd56f2506dc0aecfe568404a0a63fc19529f7c7a38ac403635f83497580b3dec2afc16b7972b4
 
 test:
-  secret_key_base: 2cd2c891cb21f0f3c32ae91f2bb6108760491b68fa7f07e89772daf5835f1c19e0aed4eaf48d16c9befc0f86fb9cb14e0adc68ac665926ad4ff6f1fcdd94281d
+  secret_key_base: 1b2d1b8c35dc3bcc8327819d95a1e635c64ae5038d25c4630463514a945c710da4923f2b8489f81021511fb59ee258e19735e50fb0df3c7efc3f06dc294c748f
 
 # Do not keep production secrets in the repository,
 # instead read values from the environment.