Add syntactic sugar "be"

[adsteel]

This custom RSpec step would minimize awkwardness from being forced to find ways to make :see work.

e.g.

expect(roles.user).to be :in_edit_mode

vs

expect(roles.user).to see :edit_mode_enabled

def is_in_edit_mode?
  visible?(:edit_button) &&
  not_visible?(:save_button)
end