add integration_data to assignment table

fixes SIS-280

:TestPlan
 -rake db:migrate
 -verify integration_data is present in assignment table
 -Add a hash into an assignment record, save record. it should save.

Change-Id: Ib4e0b06ac8b07f041e755981aec423ab6dbb8409
Reviewed-on: https://gerrit.instructure.com/35048
Reviewed-by: Duane Johnson <duane@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Jeremy Putnam <jeremyp@instructure.com>
Product-Review: Duane Johnson <duane@instructure.com>

app/models/assignment.rb

@@ -138,6 +138,7 @@ class Assignment < ActiveRecord::Base
     created_at
     updated_at
     post_to_sis
+    integration_data
   )
 
   def external_tool?
@@ -167,6 +168,8 @@ class Assignment < ActiveRecord::Base
     self.title = val
   end
 
+  serialize :integration_data, Hash
+
   serialize :turnitin_settings, Hash
   # file extensions allowed for online_upload submission
   serialize :allowed_extensions, Array

db/migrate/20140516160845_add_integration_data_to_assignment.rb

@@ -0,0 +1,11 @@
+class AddIntegrationDataToAssignment < ActiveRecord::Migration
+  tag :predeploy
+
+  def self.up
+    add_column :assignments, :integration_data, :text
+  end
+
+  def self.down
+    remove_column :assignments, :integration_data
+  end
+end