npielawski/pytorch_tiramisu: Better Tiramisu 1.0

First version with the following features:

• Memory-efficient version (trade-off between memory and speed).
• Different types of upsampling (deconvolution, upsampling and pixel shuffle).
• Different types of pooling (max-pooling, avg-pooling, blur-pooling).
• The depth and width of the Tiramisu is fully configurable.
• Early-transition can be enabled when the input images are big.
• The activation function of the last layer can be disabled or modified.