v1.2.1

• Major rewrite of DSEC dataset. It's now possible to choose from any combination of recordings, train/test split, data and targets.
• Support for target slicing in SlicedDataset. Previously we could only slice data, now we can do slicing based on data and targets.
• transforms parameter for most datasets, in addition to transform and target_transform. This allows a user to pass a transform that will be called on data and targets at the same time.
• CenterCrop transform for events, similar to what the frame-based equivalent does.
• Improvements under the hood: slicers consolidation in one file, bug fixes, documentation updates
• Exploration for the new Torch Data API under tonic/prototype. Thanks to @fabhertz95