DeprecationWarning for matplotlibs 'collections' in python 3.7

When executing the unittest "/test/test_cosmic_rays.py" with python 3.7, you get a deprecation warning for python 3.8:

test_16_plotting (main.TestCosmicRays) ... /home/marcus/.local/lib/python3.7/site-packages/matplotlib/cbook/init.py:2349: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated, and in 3.8 it will stop working if isinstance(obj, collections.Iterator): /home/marcus/.local/lib/python3.7/site-packages/matplotlib/cbook/init.py:2366: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated, and in 3.8 it will stop working return list(data) if isinstance(data, collections.MappingView) else data