NeuromorphicDataset Bug

I know that this repo is no longer maintained, but I am adding this issue here for others who might encounter the same problem.

DON'T use `self.im_template = torch.zeros((2, height, width, self.n_time_bins))` in the `__getitem(self, idx)__`  function, this will pass the tensor by reference, so they will all be the same. Construct a new zero tensor in line#136 instead.

Hope that helps!