Complete fix of the backward pass of grid_grad
What's Changed
- FIX(list_prod/sum_tensor): strongly type empty shape by @balbasty in #4
- FIX(nd): fix broadcasting error when there is a batch dimension (fix #5) by @balbasty in #6
- FIX(grid_grad) by @balbasty in #7
Full Changelog: 0.1.1...0.2.0
