Add PKLot dataset

[esnosy]

Add Dataset

• Dataset Name: PKLot
• Issue Reference: https://github.com/tensorflow/datasets/issues/4085

Description

Parking lots images database for empty/occupied parking spot classification

Checklist

• [X] Address all TODO's
• [X] Add alphabetized import to subdirectory's __init__.py
• [X] Run download_and_prepare successfully
• [X] Add checksums file
• [X] Properly cite in BibTeX format
• [ ] Add passing test(s)
• [ ] Add test data
• [ ] If using additional dependencies (e.g. scipy), use lazy_imports (if applicable)
• [ ] Add data generation script (if applicable)
• [X] Lint code

[esnosy]

any chance to get this in?