adds counter cache for user's notifications

db/migrate/20160108133501_add_notifications_counter_cache_to_user.rb

@@ -0,0 +1,5 @@
+class AddNotificationsCounterCacheToUser < ActiveRecord::Migration
+  def change
+    add_column :users, :notifications_count, :integer, default: 0
+  end
+end

db/schema.rb

@@ -11,7 +11,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20160108114750) do
+ActiveRecord::Schema.define(version: 20160108133501) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -339,6 +339,7 @@ ActiveRecord::Schema.define(version: 20160108114750) do
     t.datetime "erased_at"
     t.boolean  "public_activity",                      default: true
     t.boolean  "newsletter",                           default: false
+    t.integer  "notifications_count",                  default: 0
   end
 
   add_index "users", ["confirmation_token"], name: "index_users_on_confirmation_token", unique: true, using: :btree