Update Nimble and Quick
Remove bridging header import
Add submodule initialization to bin/setup
Rename view models

We don't need a cell specific view model. It seems like it's more useful
to have a view model that represents a specific user. That way we can do
any transformations we need to do in one place. This essentially turns
the view model into a facade for use in displaying the model.

To reduce confusion, I'm also renaming EmployeesViewModel to
EmployeeListViewModel, which is actually a little more accurate about
what it's modeling.
Add detail screen

- Basic design of the detail screen
- Add properties to EmployeeViewModel to handle the additional info
  required for the detail screen