DEPR: remove .ix from tests/indexing/multiindex/test_setitem.py
> Minor stuff but generally looks good. Are any of the items we switched from `.ix` too `.loc` duplicated in this module? If so removal would be an option as well

@WillAyd Thanks for the review.

in these PR's, i'm basically making two choices, remove code or replace with another indexer for now.

i'm hoping that this makes the review process easier.. you can just focus on the stuff removed.

This could result in some duplication. but would consider that better, in the short term, than removing useful tests.

the priority at the moment is getting .ix out of the test suite to allow the deprecation to begin. thanks @simonjayhawkins 