AttributeError: module 'matplotlib.pyplot' has no attribute 'hold'

[duichwer]

I installed openensembles and tried to use it, as is.
Then I received the error:
AttributeError: module 'matplotlib.pyplot' has no attribute 'hold'
which is caused by matplotlib>=3.0.

OpenEnsembles/openensembles/openensembles.py

Line 188 in a597bc2

plt.hold(True)

There should be a resctriction on the depencies or maybe the calls of hold could be removed?