Eval mode for ASR model and compatibility with PyTorch > 1.7

[mayank-git-hub]

• Removed the inplace operation in Residual connection by replacing x+=res with x = x + res to make the repository compatible with torch > 1.7
• Modified the dropout to be 0 in ASR to put it in eval mode

[mayank-git-hub]

This is linked to the issue https://github.com/yl4579/StarGANv2-VC/issues/72