merge Reimar's changes

10 jobs for fix_MPI in 8 minutes and 26 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Build Docker
passed build_docker_from_cache #936692

00:00:18

 
  Test
passed test_mpi #936694

00:04:45

passed test_serial #936693

00:05:23

82.0%
 
  Demo Runs
passed run_bernoulli #936699

00:00:30

passed run_curve_fitting #936700

00:00:28

passed run_getting_started_1 #936696

00:00:36

passed run_getting_started_2 #936697

00:01:04

passed run_getting_started_3 #936698

00:02:44

passed run_ipynb #936695

00:01:31

passed run_plotting_test #936701

00:00:34