Merge branch 'mpi_equality' into 'NIFTy_8'

Simplify MPI equality check

See merge request !664
16 jobs for NIFTy_8 in 34 minutes and 51 seconds (queued for 5 seconds)
Status Name Job ID Coverage
  Static Checks
passed check_no_asserts #1366166

00:00:27

 
  Build Docker
passed build_docker_from_scratch #1366168

00:13:19

 
  Test
passed test_mpi #1366175

00:00:46

passed test_serial #1366172

00:09:19

86.0%
 
  Demo Runs
passed run_bernoulli #1366191

00:00:27

passed run_curve_fitting #1366193

00:00:25

passed run_getting_density #1366189

00:08:43

passed run_getting_started_1 #1366181

00:00:35

passed run_getting_started_2 #1366183

00:00:56

passed run_getting_started_3 #1366185

00:06:08

passed run_getting_started_mf #1366187

00:08:04

passed run_ipynb0 #1366177

00:01:28

passed run_ipynb1 #1366179

00:00:48

passed run_meanfield #1366197

00:01:39

passed run_nonlinearity_guide #1366200

00:00:16

passed run_visual_vi #1366195

00:10:59