_get_weights_and_dims should accept tuple dim argument

[matt-long]

This line

esmlab/esmlab/statistics.py

Line 39 in 878b80c

elif isinstance(dim, list):

should check for iterable, not just list.

[jukent]

Thanks Matt I will look at this on Monday! Focusing on my MS thesis this weekend.

[andersy005]

Fixed in #97