Require marshmallow 4 or later - #107

Require marshmallow 4 or later#107

Marenz wants to merge 2 commits into

frequenz-floss:v1.x.xfrequenz-floss/frequenz-quantities-python:v1.x.xfrom

Marenz:marshmallow-4-compatMarenz/frequenz-quantities-python:marshmallow-4-compatCopy head branch name to clipboard