In Python 3, the types module no longer provide alternate names for
built-in types, e.g. `types.StringType` can just be spelled `str`.
NoneType is also removed; it needs to be replaced with type(None)
Reviewed-By: David Kupka <dkupka@redhat.com>
Reviewed-By: Jan Cholasta <jcholast@redhat.com>
Reviewed-By: Martin Basti <mbasti@redhat.com>