Pretrained-model loading and sharing !

Backward incompatible changes

• System is not imported from asteroid/__init__.py. This way, torch.hub doesn't need pytorch-lightning to load models. Replace your from asteroid import System calls by from asteroid.engine.system import System
• Refactor utils files into asteroid/utils folder (#120).
  The only not backward compatible behavior is when we try to import a function from torch_utils e.g from asteroid.torch_utils import pad_x_to_y. Instead, we can use from asteroid import torch_utils; torch_utils.pad_x_to_y(...)

Added

[src & egs] Publishing pretrained models !! (wham/ConvTasNet) (#125)
[src] Add License info on all (but MUSDB) supported datasets (#130)
[src & egs] Kinect-WSJ Dataset and Single channel DC Recipe (#131)
[src] Add licenses info and dataset name for model publishing
[docs] Add getting started notebook
[docs] Add notebook summary table
[egs] Enable pretrained models sharing on LibriMix (#132)
[egs] Enable wham/DPRNN model sharing (#135)
[model_cards] Add message to create model card after publishing
[model_cards] Add ConvTasNet_LibriMix_sepnoisy.md model card (Thanks @JorisCos)
[src & egs] Adding AVSpeech AudioVisual source separation (#127)
[src] Instantiate LibriMix from download with class method (#144)
[src] Add show_available_models in asteroid init
[src & tests] Bidirectional residual RNN (#146)
[src & tests] Support filenames at the input of separate (#154)

Changed

[src & hub] Remove System to reduce torch.hub deps (back to #112)
[src & tests & egs] Refactor utils files into folder (#120)
[egs] GPU id defaults to $CUDA_VISIBLE_DEVICES in all recipes (#128)
[egs] set -e in all recipes to exit or errors (#129)
[egs] Remove gpus args in all train.py (--id controls that in run.sh) (#134)
[hub] Change dataset name in LibriMix (fix)
[src] Add targets argument (to stack sources) to MUSDB18 (#143)
[notebooks] Rename examples to notebooks
[src] Enable using Zenodo without api_key argument (set ACCESS_TOKEN env variable)

Deprecated

[src] Deprecate inputs_and_masks.py (#117)
[src] Deprecate PITLossWrapper mode argument (#119)

Fixed

[src] Fix PMSQE loss (NAN backward + device placement) (#121)
[egs] Fix checkpoint.best_k_models in new PL version (#123)
[egs] Fix: remove shuffle=True in validation Loader (lightning error) (#124)
[egs] Corrections on LibriMix eval and train and evals scripts (#137)
[egs] Fix wavfiles saving in eval.py for enh_single and enh_both tasks (closes #139)
[egs] Fix wavfiles saving in eval.py for enh tasks (estimates)
[egs] Fix #139 : correct squeeze for enhancement tasks (#142)
[egs] Fix librimix run.sh and eval.py (#148)