There's no functional changes here other than moving the initializer
documentation for the 'DeprecatedRule' from the '__init__' docstring to
the class' docstring. This allows us to remove '__init__' entirely since
it was just calling the superclass.
Change-Id: I7437cf00b2ba5c02926dc8c2435e237ef730f2b1
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>