New API for passing transform functions

• Consistent API for pass transform functions
• Clean the code

Full Changelog: 0.2.0...0.2.1

New API compatible with all pytorch dataloder arguments, bug fixes

• Add dataloder_kws to grant loaders the ability to accept all dataloader arguments
• writer function name adjustment
• Several bug fixes

Full Changelog: 0.1.1...0.2.0

Patch fix: Unittest, Dependencies

Add unittest module
Fix some errors on dependencies

Full Changelog: 0.1.0...0.1.1

Pre-alpha version: pytorch dataloader, webdataset support

1. Add writer and loader for webdataset,
2. Provide pytorch dataloader wrapper
3. Provide pytorch-lightning datamodule wrapper