e2e Testing Changes

- Added a e2e test that deletes data, which prompted...
- Added some helper scripts to automatically reset the Rails environment (i.e., the database) so the e2e tests have a predictable test environment to work with. I'm choosing this approach because e2e tests should test the "full stack", which includes real database transactions and server responses, not mock responses like unit tests (although I've seen people use mock responses in e2e, which I disagree with).
Expanded e2e Testing.
Expanded e2e Testing (again).
Added Directive That Wraps jQuery UI Sortable.