Add tests for steam boilers#71

simonvoelcker wants to merge 1 commit intofrequenz-floss:v0.x.xfrequenz-floss/frequenz-microgrid-component-graph-python:v0.x.xfrom

simonvoelcker:add-steam-boilersimonvoelcker/frequenz-microgrid-component-graph-python:add-steam-boilerCopy head branch name to clipboard