Example folder needs updating: ChannelIndex is not working

[disadone]

I am new to neo.
https://github.com/NeuralEnsemble/python-neo/blob/master/examples/generated_data.py is written four years ago. ChannelIndex is gone but examples are not refreshed.
Hopefully examples folder can be refreshed.
Thanks!

[JuliaSprenger]

Hi @disadone. Thanks for reporting.
@apdavison Do you want to include this in #1178 or should I open a new PR?

[JuliaSprenger]

This issue still persists even with #1178 merged.

[zm711]

I have an open PR #1333, to work on this when I get time. It's just a draft at the moment so someone else can pick it up, but I'll keep working on it when I can.