introduce organizations

app/models/conference.rb

@@ -7,6 +7,8 @@ class Conference < ActiveRecord::Base
 
   default_scope { order('start_date DESC') }
 
+  belongs_to :organization
+
   has_paper_trail ignore: %i(updated_at guid revision events_per_week), meta: { conference_id: :id }
 
   has_and_belongs_to_many :questions
@@ -53,7 +55,8 @@ class Conference < ActiveRecord::Base
             :start_date,
             :end_date,
             :start_hour,
-            :end_hour, presence: true
+            :end_hour,
+            :organization, presence: true
 
   validates :short_title, uniqueness: true
   validates :short_title, format: { with: /\A[a-zA-Z0-9_-]*\z/ }

app/models/organization.rb

@@ -0,0 +1,7 @@
+class Organization < ActiveRecord::Base
+  has_many :conferences, dependent: :destroy
+
+  validates :name, presence: true
+
+  mount_uploader :picture, PictureUploader, mount_on: :picture
+end