Add CallLog, no code uses yet

twilio/app/models/call_log.rb

+class CallLog < ActiveRecord::Base
+  belongs_to :message
+end

twilio/app/models/message.rb

   validates :title, presence: true
   validates :body, presence: true
   validates :secret, presence: true, uniqueness: true
+
+  has_many :call_logs
 end

twilio/db/migrate/20140903035305_create_call_logs.rb

+class CreateCallLogs < ActiveRecord::Migration
+  def change
+    create_table :call_logs do |t|
+      t.text :number
+      t.references :message, index: true
+
+      t.timestamps
+    end
+  end
+end