Logical bug in the code

[yfeizhang]

Hi folks, thanks for your excellent work!
I have used the repo and I found a very key bug in the following position.
Actually, in your model architecture, there is no layer called ".fc", therefore, directly replace to identity layer will not transfer the network architecture to embedder (actually not change the network architecture at all, just add another identity layer in the network class not to use). It is better to fix the bug in the repo.
https://github.com/ruoxi-jia-group/LAVA/blob/84e8bd55e62239625d8728240ec041d2fca5b2f4/lava.py#L88