run_tests: remove *everything* that starts with tmp before each set of tests
run_tests: remove *everything* that starts with tmp before each set of tests

MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3