Wrong case of class variable inside `TinyCIFAR10DataModule`

[ggalan87]

🐛 Bug

Prior to utilization of TinyCIFAR10DataModule I did a check on its (under review) code. Ι realized that there is a bug/typo inside __init__, where self.extra_args variable is set:

https://github.com/Lightning-Universe/lightning-bolts/blob/2fdb8185e24696049846a9bcdd31c802d10abc96/pl_bolts/datamodules/cifar10_datamodule.py#L182

This is in contrast to self.EXTRA_ARGS which is already defined and used by the methods of the base class as required to pass the correct extra arguments to the underlying dataset:

https://github.com/Lightning-Universe/lightning-bolts/blob/2fdb8185e24696049846a9bcdd31c802d10abc96/pl_bolts/datamodules/vision_datamodule.py#L105-L106

A similar case that self.extra_args is used is inside CityscapesDataModule, however there the implementation is self-contained and does not depend on base class for train_dataloader and test_dataloader.

Besides the bug, is there a motivation about why a capitalized version of the variable was preferred inside VisionDataModule?