Try to make windows testing more reliable.
Try to make windows testing more reliable.

For some reason, this notebook was triggering errors
"RuntimeError: NetCDF: Not a valid ID" on "ncfile.close()". It looks
like some kind of weird threading/race due to the timeits. I've moved
opening the dataset out of the benchmarking, which will hopefully
eliminate this problem.

Unidata/unidata-python-workshop,julienchastang/unidata-python-workshop,julienchastang/unidata-python-workshop