- bugfix in TimeStepFluidModel #55

Job	Run time
build-manylinux-python (cp37-cp37m)	59s
build-manylinux-python (cp39-cp39)	1m 5s
build-manylinux-python (cp38-cp38)	1m 4s
build-manylinux-python (cp310-cp310)	1m 11s
build-manylinux-python (cp36-cp36m)	1m 2s
build-ubuntu	10m 9s
	15m 30s

Provide feedback