osra289: partners#index controller&view

Add partners#index controller and view

OSRA-289 #Code-Review
Broken links would naturally force BDD, whereas if `admin_.._path` links are in place, the first step in building a new feature/page will have to be changing them to `hq_.._path` to get failing tests.

I think that we and the client can tolerate broken links on staging and even production since this entire interface will not be easily accessible until the switch is flipped. As long as broken links don't compromise the underlying data, they are a mere UI inconvenience that the client is unlikely to run into anyway. That said, it's probably a good idea to give the client a heads-up about this branch of development.