Climix does not gracefully handle single node / singe core

Climix crashes when running on a shared node with interactive -N 1 -n 1:

 >climix -s -e  -x txx  /home/rossby/prod/201137/netcdf/day/tasmax_EUR-11_ICHEC-EC-EARTH_historical_r12i1p1_SMHI-RCA4_v1_day_*.nc
INFO:root:Loading metadata
Traceback (most recent call last):
  File "/home/sm_lbarr/.conda/envs/climix-devel-3/bin/climix", line 11, in <module>
    load_entry_point('climix', 'console_scripts', 'climix')()
  File "/home/sm_lbarr/CODE/climix/climix/main.py", line 146, in main
    with setup_scheduler(args) as scheduler:
  File "/home/sm_lbarr/CODE/climix/climix/dask_setup.py", line 160, in setup_scheduler
    return scheduler(**scheduler_kwargs)
  File "/home/sm_lbarr/CODE/climix/climix/dask_setup.py", line 68, in __init__
    memory_limit = (system.MEMORY_LIMIT*.9) / n_workers
ZeroDivisionError: float division by zero

Preferably it should instead give a graceful error message.