Fix bug on master
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them

The banklist file was removed and replaced with banklist.csv. This causes failures on master.

This is just a temporary fix for the user guide.

cc @jreback

thanks for fixing @phofl  @meeseeksdev backport 1.2.x