[Bug fix] redundant layers in ResNet

[keineahnung2345]

In https://github.com/yunjey/pytorch-tutorial/blob/master/tutorials/02-intermediate/deep_residual_network/main.py#L115, it defined a length 4 layers. But in https://github.com/yunjey/pytorch-tutorial/blob/master/tutorials/02-intermediate/deep_residual_network/main.py#L84, it only uses layers[0] and layers[1]. So the last entry of [2,2,2,2] should be redundant.

[yunjey]

@keineahnung2345 You are right. Thanks very much.