Runtime warnings

[cglewis]

/usr/local/lib/python3.7/site-packages/numpy/core/_methods.py:161
  /usr/local/lib/python3.7/site-packages/numpy/core/_methods.py:161: RuntimeWarning: invalid value encountered in double_scalars
    ret = ret.dtype.type(ret / rcount)

/usr/local/lib/python3.7/site-packages/numpy/core/fromnumeric.py:3257
  /usr/local/lib/python3.7/site-packages/numpy/core/fromnumeric.py:3257: RuntimeWarning: Mean of empty slice.
    out=out, **kwargs)

/usr/local/lib/python3.7/importlib/_bootstrap.py:219
  /usr/local/lib/python3.7/importlib/_bootstrap.py:219: RuntimeWarning: numpy.ufunc size changed, may indicate binary incompatibility. Expected 216, got 192
    return f(*args, **kwds)

[cglewis]

numpy.ufunc size changed can be ignored, as it's benign and an issue that numpy/scikit have to address.