Add demo code for the original GEM

Remove duplicated memory operation in GEM

Enable rehearsal data augmentation for CIFAR exp

Add cifar100 results

Support torchvision 0.3.0

Add the scripts for cifar100

fix bibtex

fix the indent of comment

update readme

Add figures

Update readme and comments

Add GEM (Gradient Episodic Memory for Continual Learning)

remove the deprecated argument (async).

Add module

Initial check in