Orphan list

First two tasks of PT story https://www.pivotaltracker.com/story/show/76239760

- [x] Create Orphan List model
- [x] Create new and index views for orphan lists
- [ ] Write cucumber features for testing orphan list creation and file upload 
- [ ] Switch to S3 for file storage
I'm not so sure this required indexing. I guess we don't have a case where we need to look up orphan lists by their osra_num.