sparse fails to import with NumPy 1.15 installed

[shoyer]

In [1]: import sparse
---------------------------------------------------------------------------
ModuleNotFoundError                       Traceback (most recent call last)
<ipython-input-1-5d03fa13bb7b> in <module>()
----> 1 import sparse

~/dev/sparse/sparse/__init__.py in <module>()
----> 1 from .coo import *
      2 from .compressed import GXCS
      3 from .dok import DOK
      4 from .sparse_array import SparseArray
      5 from .utils import random

~/dev/sparse/sparse/coo/__init__.py in <module>()
      6                      kron, argwhere, isposinf, isneginf)
      7
----> 8 from numpy.core._multiarray_umath import result_type
      9
     10 __all__ = ['COO', 'as_coo', 'elemwise', 'tensordot', 'dot', 'matmul', 'concatenate', 'stack', 'triu', 'tril', 'where', 'nansum', 'nanmean',

ModuleNotFoundError: No module named 'numpy.core._multiarray_umath'

The issue seems to be the use of NumPy's internal/private APIs, as noted in: #261