Added Subscription model to send emails

app/models/conference.rb

@@ -49,7 +49,7 @@ class Conference < ActiveRecord::Base
   has_many :targets, dependent: :destroy
   has_many :campaigns, dependent: :destroy
   has_many :commercials, as: :commercialable, dependent: :destroy
-  belongs_to :venue
+  has_many :subscriptions, dependent: :destroy
 
   accepts_nested_attributes_for :rooms, reject_if: proc { |r| r['name'].blank? }, allow_destroy: true
   accepts_nested_attributes_for :tracks, reject_if: proc { |r| r['name'].blank? }, allow_destroy: true

app/models/subscription.rb

@@ -0,0 +1,5 @@
+class Subscription < ActiveRecord::Base
+  attr_accessible :user_id, :conference_id
+  belongs_to :conference
+  belongs_to :user
+end

app/models/user.rb

@@ -20,7 +20,7 @@ class User < ActiveRecord::Base
   has_many :registrations, dependent: :destroy
   has_many :votes, dependent: :destroy
   has_many :voted_events, through: :votes, source: :events
-
+  has_many :subscriptions, dependent: :destroy
   accepts_nested_attributes_for :roles
 
   before_create :setup_role

db/migrate/20140724153520_create_subscriptions.rb

@@ -0,0 +1,9 @@
+class CreateSubscriptions < ActiveRecord::Migration
+  def change
+    create_table :subscriptions do |t|
+      t.belongs_to :user
+      t.belongs_to :conference
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -408,6 +408,13 @@ ActiveRecord::Schema.define(version: 20140801170430) do
     t.datetime "updated_at"
   end
 
+  create_table "subscriptions", force: true do |t|
+    t.integer  "user_id"
+    t.integer  "conference_id"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
   create_table "supporter_levels", force: true do |t|
     t.integer "conference_id"
     t.string  "title",         null: false