Add schedule model

app/models/hall.rb

@@ -0,0 +1,3 @@
+class Hall < ActiveRecord::Base
+  belongs_to :conference
+end

app/models/slot.rb

@@ -0,0 +1,4 @@
+class Slot < ActiveRecord::Base
+  belongs_to :hall
+  belongs_to :event
+end

db/migrate/20141012100900_create_halls.rb

@@ -0,0 +1,10 @@
+class CreateHalls < ActiveRecord::Migration
+  def change
+    create_table :halls do |t|
+      t.references :conference, index: true
+      t.string :name
+
+      t.timestamps
+    end
+  end
+end

db/migrate/20141012101004_create_slots.rb

@@ -0,0 +1,12 @@
+class CreateSlots < ActiveRecord::Migration
+  def change
+    create_table :slots do |t|
+      t.references :hall, index: true
+      t.timestamp :starts_at, null: false
+      t.timestamp :ends_at, null: false
+      t.references :event, index: true
+
+      t.timestamps
+    end
+  end
+end