Fix BatchRandTransform & PitchShift

[warner-benjamin]

Resolves #23.

[vishalbakshi]

@warner-benjamin I tested this on Kaggle and it works as expected:

# installing from the transfom_fixes branch
!pip install colorednoise primePy git+https://github.com/warner-benjamin/fastxtend.git@transform_fixes -qq

auds.summary(df) runs successfully when the DataBlock has PitchShift as batch_tfms:

Ran auds.summary with batch_tfms equal to VolumeBatch, PitchShiftTA, TimeStretch and PitchShiftOrTimeStretch and it works. Also trained a resnet18 for a few epochs just to make sure and it trains successfully.

---

My first preference was to test it locally on my machine so I got fastxtend cloned and installed (w/ pip install -e .) but I have macOS 11.6 so I was getting the following error when running auds.summary(df):

RuntimeError: The MPS backend is supported on MacOS 12.3+.Current OS version can be queried using `sw_vers`

Which I don't think can be resolved until I upgrade to 12.3+.

[warner-benjamin]

@vishalbakshi thanks for testing the fix. I wouldn't expect fastxtend to work on MPS. I've coded everything with Cuda or CPU in mind, and don't have a modern mac to do any testing on.