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
If they wanted to look up a particular list, they will either get to it from one of the orphans or from the partner. In both cases, lookup will be based on the foreign key in the associated models against `id` column (which is indexed by default) and it will not be based on the osra_num.