Using `np.dtype(int)` instead of `np.int64`.
Using `np.dtype(int)` instead of `np.int64`.

See 32-bit failure on Windows:
https://ci.appveyor.com/project/dhermes/bezier/builds/27101355/job/uqtns0a2ctlkaa6c

dhermes/bezier,dhermes/bezier,dhermes/bezier