Pytorch 1.9 linalg package compatibility

0.4

Version 0.4 incorporating new pytorch's linalg for version >1.9

Torch.fft compatibility

Deprecating torch.rfft and torch.ifft in favor of Pytorch's fft package following their road map.
This changes are only applied for pytorch>1.7.

0.2

Update README.md

0.1

Update README.md