Ignore changes to superuser credentials example. Won't change format
Added Page fixtures for Index and About us Page, updated tests.

* These fixtures reduce the amount of copy/pasting of the same code we
  have to do in the tests.
* Tests have been updated to use these new fixtures and play nicely
  with them.
Remove `spec/views/admin` files.
Wrote tests for the Admin::PagesController

* Confirm that resources are created/displayed/edited/destroyed as we
  expect
* also test that each action is only accessible for admins.