simple_example.py does not work for coffea CalVer

[kpedro88]

The provided simple_example.py fails immediately in CalVer:

Traceback (most recent call last):
  File "/srv/simple_example.py", line 4, in <module>
    from coffea import hist, processor, nanoevents
ImportError: cannot import name 'hist' from 'coffea' (/usr/local/lib/python3.11/site-packages/coffea/__init__.py)

I'm not sure if there's a standard conditional import statement to get around this or if it's even desirable to maintain the example for both 0.7 and CalVer.

[lgray]

Thanks for the catch - I had converted it a long time ago and tested it but never pushed it!
Will get to it.