Deep-pipe

- Renamed `axes` argument to `axis` throughout the library
- Significantly faster sampling sources in `dpipe.batch_iter`
- More extensions are supported by `load` and `save` from `dpipe.io`

- Renamed `dpipe.medim` to `dpipe.im`. Moved all medical-related code to separate repositories. `dpipe.medim` will still be importable until the next release
- Support for adaptive batch size in batch iterators. To ensure reproducibility, `sources` now have a `random_state` argument
- Experiment layouts - a new, simpler way to build and run experiments
- Various fixes

- Got rid of Snakemake.
- Added functions with bindings to the configs grammar.
- Added `dicom_utils`.
- Removed a lot of deprecated stuff and reorganized some modules' structure.