Implement sponsor feature and add adiitonal scenarios for earlier features

Part of PT story https://www.pivotaltracker.com/story/show/76232594

- add more tests to admin users feature
- add additional scenario to partner featue
- added sponsor feature 
- fix delete links being show for sponsors by active admin
- added linked name to sponsor index view
- refactored authenticated user step into background
12004? We create 3 partners in the background.
I think putting it there is too brittle.
Options are:
- its own scenario maybe checking partner1, partner2, partner3 (this too could be brittle)
- have an rspec test for it.
- have both

What are your thoughts?