matplotlib unexpected keyword argument

[sametz]

Running the demo Jupyter notebooks, the following type of error was seen when plotting "stick"-style plots:

/srv/conda/envs/notebook/lib/python3.7/site-packages/matplotlib/cbook/deprecation.py:107: MatplotlibDeprecationWarning: stem() got an unexpected keyword argument 'use_line_collection'. This will raise a TypeError in future versions.
  warnings.warn(message, mplDeprecation, stacklevel=1)