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