added sponsor feature and fixed ui sponsor issues

part of pivotal tracker story https://www.pivotaltracker.com/story/show/76232594
1. created the feature for integration testing
2. remove ability to delete a sponsor from active admin
3. added linkable name to the listing in the index view
added scenario to admin user feature checking for delete links on index page

part of pivotal tracker story https://www.pivotaltracker.com/story/show/76232594