MAINT: fix non-integer usage in scipy.spatial.
MAINT: fix non-integer usage in cluster and sparse.
MAINT: fix non-integer usage in io, interpolate and optimize.
MAINT: incorrect non-integer usage fixes: address comments @charris on pr-2533.
MAINT: fix one more occurrence of np.prod inside reshape.
Merge pull request #2533 from rgommers/fix-nonint-usage

Fix incorrect non-integer usage in function calls.