diff --git a/Gemfile b/Gemfile
index d74ba069..a1e081f6 100644
--- a/Gemfile
+++ b/Gemfile
@@ -32,7 +32,7 @@ gem 'carrierwave-bombshelter'
 gem 'mini_magick'
 
 # for internationalizing
-gem 'rails-i18n', '~> 5.0.0'
+gem 'rails-i18n'
 
 # as authentification framework
 gem 'devise'
@@ -49,7 +49,7 @@ gem 'omniauth-openid'
 gem 'recaptcha', require: 'recaptcha/rails'
 
 # as authorization framework
-gem 'cancancan', '~> 2.0'
+gem 'cancancan'
 
 # for roles
 gem 'rolify'
@@ -62,7 +62,7 @@ gem 'transitions', :require => %w( transitions active_record/transitions )
 
 # for comments
 gem 'acts_as_commentable_with_threading'
-gem 'awesome_nested_set', '~> 3.1.3'
+gem 'awesome_nested_set'
 
 # as templating language
 gem 'haml-rails'
@@ -87,8 +87,6 @@ gem 'jquery-ui-rails', '~> 4.2.1'
 # for languages validation
 gem 'iso-639'
 
-gem 'thor', '~> 0.19'
-
 # frontend javascripts
 source 'https://rails-assets.org' do
   # for placeholder images
@@ -135,7 +133,7 @@ gem 'gravtastic'
 gem 'country_select'
 
 # as PDF generator
-gem 'prawn-qrcode', '~> 0.3.0'
+gem 'prawn-qrcode'
 gem 'prawn_rails'
 gem 'rqrcode'
 
@@ -144,7 +142,7 @@ gem 'axlsx', git: 'https://github.com/randym/axlsx.git'
 gem 'axlsx_rails'
 
 # as error catcher
-gem 'airbrake', '~> 7.1'
+gem 'airbrake'
 
 # to make links faster
 gem 'turbolinks'
@@ -181,7 +179,7 @@ gem 'acts_as_list'
 gem 'bootstrap-switch-rails', '~> 3.0.0'
 
 # for parsing OEmbed data
-gem 'ruby-oembed', '~>0.12.0'
+gem 'ruby-oembed'
 
 # for uploading images to the cloud
 gem 'cloudinary'
@@ -194,7 +192,7 @@ gem 'dotenv-rails'
 gem 'feature'
 
 # For countable.js
-gem "countable-rails", "~> 0.0.1"
+gem "countable-rails"
 
 # Both are not in a group as we use it also for rake data:demo
 # for fake data
@@ -236,7 +234,7 @@ group :development do
   # as deployment system
   gem 'mina'
   # as debugger on error pages
-  gem 'web-console', '~> 2.0'
+  gem 'web-console'
   # as development database
   gem 'sqlite3'
 end
diff --git a/Gemfile.lock b/Gemfile.lock
index 25bdca92..af2c9ada 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -64,9 +64,10 @@ GEM
     addressable (2.6.0)
       public_suffix (>= 2.0.2, < 4.0)
     afm (0.2.2)
-    airbrake (7.4.0)
-      airbrake-ruby (~> 2.12)
-    airbrake-ruby (2.12.0)
+    airbrake (9.0.0)
+      airbrake-ruby (~> 4.2)
+    airbrake-ruby (4.2.2)
+      rbtree3 (~> 0.5)
     ajax-datatables-rails (0.4.3)
       railties (>= 4.0)
     archive-zip (0.12.0)
@@ -82,8 +83,7 @@ GEM
       actionpack (>= 3.1)
       axlsx (>= 2.0.1)
     bcrypt (3.1.12)
-    binding_of_caller (0.8.0)
-      debug_inspector (>= 0.0.1)
+    bindex (0.6.0)
     bootstrap-sass (3.4.1)
       autoprefixer-rails (>= 5.2.1)
       sassc (>= 2.0.0)
@@ -147,7 +147,6 @@ GEM
     dalli (2.7.10)
     dante (0.2.0)
     database_cleaner (1.7.0)
-    debug_inspector (0.0.3)
     delayed_job (4.1.5)
       activesupport (>= 3.0, < 5.3)
     delayed_job_active_record (4.1.3)
@@ -235,7 +234,7 @@ GEM
     htmlentities (4.3.4)
     http-cookie (1.0.3)
       domain_name (~> 0.5)
-    i18n (0.9.5)
+    i18n (1.6.0)
       concurrent-ruby (~> 1.0)
     i18n_data (0.8.0)
     inversion (1.1.1)
@@ -422,9 +421,9 @@ GEM
       nokogiri (>= 1.6)
     rails-html-sanitizer (1.0.4)
       loofah (~> 2.2, >= 2.2.2)
-    rails-i18n (5.0.4)
-      i18n (~> 0.7)
-      railties (~> 5.0)
+    rails-i18n (5.1.3)
+      i18n (>= 0.7, < 2)
+      railties (>= 5.0, < 6)
     railties (5.0.7.2)
       actionpack (= 5.0.7.2)
       activesupport (= 5.0.7.2)
@@ -436,6 +435,7 @@ GEM
     rb-fsevent (0.10.3)
     rb-inotify (0.10.0)
       ffi (~> 1.0)
+    rbtree3 (0.5.0)
     rdoc (6.0.4)
     rdoc-generator-fivefish (0.4.0)
       inversion (~> 1.1)
@@ -582,11 +582,11 @@ GEM
     url (0.3.2)
     warden (1.2.8)
       rack (>= 2.0.6)
-    web-console (2.3.0)
-      activemodel (>= 4.0)
-      binding_of_caller (>= 0.7.2)
-      railties (>= 4.0)
-      sprockets-rails (>= 2.0, < 4.0)
+    web-console (3.7.0)
+      actionview (>= 5.0)
+      activemodel (>= 5.0)
+      bindex (>= 0.4.0)
+      railties (>= 5.0)
     webmock (3.5.1)
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
@@ -607,17 +607,17 @@ DEPENDENCIES
   active_model_serializers
   acts_as_commentable_with_threading
   acts_as_list
-  airbrake (~> 7.1)
+  airbrake
   ajax-datatables-rails
   autoprefixer-rails
-  awesome_nested_set (~> 3.1.3)
+  awesome_nested_set
   axlsx!
   axlsx_rails
   bootstrap-sass (~> 3.4.0)
   bootstrap-switch-rails (~> 3.0.0)
   bootstrap3-datetimepicker-rails (~> 4.17.47)
   byebug
-  cancancan (~> 2.0)
+  cancancan
   capybara
   carrierwave
   carrierwave-bombshelter
@@ -627,7 +627,7 @@ DEPENDENCIES
   cloudinary
   cocoon
   codecov
-  countable-rails (~> 0.0.1)
+  countable-rails
   country_select
   daemons
   dalli
@@ -668,7 +668,7 @@ DEPENDENCIES
   pdf-inspector
   pg
   piwik_analytics (~> 1.0.1)
-  prawn-qrcode (~> 0.3.0)
+  prawn-qrcode
   prawn_rails
   puma (~> 3.0)
   rails (~> 5.0.7)
@@ -685,7 +685,7 @@ DEPENDENCIES
   rails-assets-trianglify!
   rails-assets-waypoints!
   rails-controller-testing
-  rails-i18n (~> 5.0.0)
+  rails-i18n
   rdoc-generator-fivefish
   recaptcha
   redcarpet
@@ -696,7 +696,7 @@ DEPENDENCIES
   rspec-rails
   rubocop
   rubocop-rspec
-  ruby-oembed (~> 0.12.0)
+  ruby-oembed
   sass-rails (>= 4.0.2)
   selectize-rails
   selenium-webdriver
@@ -707,14 +707,13 @@ DEPENDENCIES
   sqlite3
   stripe
   stripe-ruby-mock
-  thor (~> 0.19)
   timecop
   transactional_capybara
   transitions
   turbolinks
   uglifier (>= 1.3.0)
   unobtrusive_flash (>= 3)
-  web-console (~> 2.0)
+  web-console
   webmock
   whenever
 
@@ -722,4 +721,4 @@ RUBY VERSION
    ruby 2.5.0p0
 
 BUNDLED WITH
-   1.17.1
+   1.17.3