rfr_ Adding pagination

Added pagination + specs for the user page available to the admin and to the bus page available to the user.
This setup builds some extra objects for each test that we don't need.  If our admin test, we just need our `@admin` and dummy users.  In our user test, we just need our `@user` and dummy buses.  Running this `before :each` block before both of our tests will slow our tests down unnecessarily.

Instead, I'd do all your setup inside your tests.  I'd also take advantage of FactoryGirl's `create_list` method to create multiple objects at a time.

Note that if you change the number of items displayed per page from 3 to 20-25, you'll need to create more than 20 or 25 objects to successfully test pagination.