{
   "finished_at":null,
   "id":21,
   "migration_type":"canvas_cartridge_importer",
   "started_at":null,
   "user_id":1,
   "workflow_state":"pre_processing",
   "created_at":"2014-08-08T16:54:25Z",
   "migration_issues_url":"http://host/api/v1/courses/659/content_migrations/21/migration_issues",
   "migration_issues_count":0,
   "pre_attachment":{
      "upload_url":"http://host/files_api",
      "upload_params":{
         "Filename":"",
         "key":"/cc.imscc",
         "acl":"private",
         "Policy":"eyJleHBpcmF0aW9uIjoiMjAxNC0wOC0wOFQxNzoyNDoyNloiLCJjb25kaXRpb25zIjpbeyJrZXkiOiIvVXNlcnMvYnJhbmRvbmJyL3dvcmsvc3JjL2NhbnZhcy9jYW52YXMtbG1zLXdvcmtpbmcvdG1wL2ZpbGVzLzAwMDAvMDI5My9zdTEyX2JsX2VkdWNfcHJhY180NzE0Mi5pbXNjYyJ9LHsiYWNsIjoicHJpdmF0ZSJ9LFsic3RhcnRzLXdpdGgiLCIkRmlsZW5hbWUiLCIiXSxbImNvbnRlbnQtbGVuZ3RoLXJhbmdlIiwxLDEwNzM3NDE4MjQwXSx7InBzZXVkb255bV9pZCI6MX1dLCJhdHRhY2htZW50X2lkIjoyOTN9",
         "Signature":"OyXpEfbSmp79ZD/WCQKlhz0u2mo="
      },
      "file_param":"attachment[uploaded_data]"
   },
   "migration_type_title":"Canvas Common Cartridge"
}