Do not run test_io in parallel

Author: mikaem

tests/runtests.sh

@@ -24,8 +24,8 @@ if [ $PY -eq 3 ]; then
     # mpiexec -n  8 python -m coverage test_mpifft.py
     # mpiexec -n 12 python -m coverage test_mpifft.py
     mpiexec -n 2 python -m coverage run spectral_dns_solver.py
-    mpiexec -n 2 python -m coverage run -m test_io
-    mpiexec -n 4 python -m coverage run -m test_io
+    #mpiexec -n 2 python -m coverage run -m test_io
+    #mpiexec -n 4 python -m coverage run -m test_io
     mpiexec -n 2 python -m coverage run -m test_darray
     mpiexec -n 4 python -m coverage run -m test_darray