Add rails observers

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Gemfile

@@ -14,6 +14,7 @@ gem 'actionpack-page_caching'
 gem 'actionpack-action_caching'
 gem 'activerecord-deprecated_finders'
 gem 'activerecord-session_store'
+gem "rails-observers"
 # DB
 gem 'mysql2', group: :mysql

Gemfile.lock

@@ -194,6 +194,8 @@ GEM
       bundler (>= 1.3.0, < 2.0)
       railties (= 4.0.2)
       sprockets-rails (~> 2.0.0)
+    rails-observers (0.1.2)
+      activemodel (~> 4.0)
     railties (4.0.2)
       actionpack (= 4.0.2)
       activesupport (= 4.0.2)
@@ -332,6 +334,7 @@ DEPENDENCIES
   puma (~> 2.7.1)
   quiet_assets
   rails (= 4.0.2)
+  rails-observers
   rake
   rb-fsevent
   rb-inotify