OpenMPI 3.0 support
OpenMPI 3.0 by default does not allow running with more processes than CPUs, which caused many tests to fail on my laptop. This merge request enables --oversubscribe on all tests if the OpenMPI version is greater than 3.
OpenMPI 3.0 by default does not allow running with more processes than CPUs, which caused many tests to fail on my laptop. This merge request enables --oversubscribe on all tests if the OpenMPI version is greater than 3.