TST: test reset_index with tuple index name and col_level!=0
 - [x] tests added / passed
 - [x] passes ``git diff master --name-only -- '*.py' | flake8 --diff``

This just completes #16165 as [asked](https://github.com/pandas-dev/pandas/pull/16165#issuecomment-298427315) by @jorisvandenbossche 