Bundle update, and some gems don't need anymore a fixed version

Gemfile

@@ -31,7 +31,7 @@ gem 'http_accept_language'
 # Remove leading and trailing white spaces
 gem 'strip_attributes'
 # Track changes to models' data
-gem 'paper_trail', '~> 4.0.0.rc'
+gem 'paper_trail'
 
 # Validate mails submitted
 gem 'email_validator'
@@ -71,7 +71,7 @@ group :development do
   gem 'quiet_assets'
 
   # Access an IRB console on exception pages or by using <%= console %> in views
-  gem 'web-console', '~> 2.0'
+  gem 'web-console'
 
   gem 'guard-migrate', require: false
   gem 'guard-bundler', require: false
@@ -100,8 +100,7 @@ group :development, :test do
 end
 
 group :development, :test, :assets do
-  # Use SASS for stylesheets, this version is required to compile active_admin
-  # assets, TODO
+  # Use SASS for stylesheets
   gem 'sass-rails'
   # Use CoffeeScript for .coffee assets and views
   gem 'coffee-rails'
@@ -114,7 +113,7 @@ group :development, :test, :assets do
   gem 'turbolinks'
   gem 'jquery-turbolinks'
   # bundle exec rake doc:rails generates the API under doc/api.
-  gem 'sdoc', '~> 0.4.0', group: :doc
+  gem 'sdoc', group: :doc
 
   gem 'compass-rails', github: 'Compass/compass-rails'
   gem 'modernizr-rails'
@@ -123,6 +122,7 @@ group :development, :test, :assets do
   gem 'webshims-rails'
 
   # Improve the html select element
+  # Later version disabled the tag selector...
   gem 'select2-rails', '< 4'
 
   # A superb font to use as icons
@@ -138,5 +138,5 @@ end
 
 group :production do
   # Use mysql as the database for Active Record
-  gem 'mysql2', '~> 0.3.18'
+  gem 'mysql2'
 end

Gemfile.lock

@@ -83,8 +83,6 @@ GEM
     arel (6.0.3)
     ast (2.2.0)
     bcrypt (3.1.11)
-    binding_of_caller (0.7.2)
-      debug_inspector (>= 0.0.1)
     bourbon (4.2.6)
       sass (~> 3.4)
       thor (~> 0.19)
@@ -265,7 +263,7 @@ GEM
     modernizr-rails (2.7.1)
     multi_json (1.11.2)
     multipart-post (2.0.0)
-    mysql2 (0.3.20)
+    mysql2 (0.4.3)
     naught (1.1.0)
     nenv (0.3.0)
     nokogiri (1.6.7.2)
@@ -274,7 +272,7 @@ GEM
       nenv (~> 0.1)
       shellany (~> 0.0)
     orm_adapter (0.5.0)
-    paper_trail (4.0.2)
+    paper_trail (4.1.0)
       activerecord (>= 3.0, < 6.0)
       activesupport (>= 3.0, < 6.0)
       request_store (~> 1.1)
@@ -426,11 +424,10 @@ GEM
     unicode-display_width (1.0.2)
     warden (1.2.6)
       rack (>= 1.0)
-    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 (3.1.1)
+      activemodel (>= 4.2)
+      debug_inspector
+      railties (>= 4.2)
     webrick (1.3.1)
     webshims-rails (1.15.10)
       rails (> 3.1.0)
@@ -471,15 +468,15 @@ DEPENDENCIES
   leaflet-rails
   meta-tags
   modernizr-rails
-  mysql2 (~> 0.3.18)
-  paper_trail (~> 4.0.0.rc)
+  mysql2
+  paper_trail
   quiet_assets
   rack-livereload
   rails
   rails-i18n
   redcarpet
   sass-rails
-  sdoc (~> 0.4.0)
+  sdoc
   select2-rails (< 4)
   simple_calendar
   simplecov
@@ -492,7 +489,7 @@ DEPENDENCIES
   turbolinks
   twitter
   uglifier
-  web-console (~> 2.0)
+  web-console
   webrick
   webshims-rails