Fix test for newer numpy
Fix test for newer numpy

Exception message is different now:
IndexError: index 5 is out of bounds for axis 0 with size 2
while it used to be:
IndexError: index 5 is out of bounds for axis 1 with size 2
the new one makes more sense, as this is a 1d-array.

TeamHG-Memex/eli5,TeamHG-Memex/eli5,TeamHG-Memex/eli5