GitLab

* Added LFW Dataset

* Added dataset to list in __init__.py

* Updated lfw.py
* Created a common superclass for people and pairs type datatsets
* corrected the .download() method

* Added docstrings and updated datasets.rst

* Wrote tests for LFWPeople and LFWPairs

* Resolved mypy error: Need type annotation for "data"

* Updated inject_fake_data method for LFWPeople

* Updated tests for LFW

* Updated LFW tests and minor changes in lfw.py

* Updated LFW
* Added functionality for 10-fold validation view
* Optimized the code so to replace repeated lines by method in super
  class
* Updated LFWPeople to get classes from all lfw-names.txt rather than
  just the classes fron trainset

* Updated lfw.py and tests
* Updated inject_fake_data method to create 10fold fake data
* Minor changes in docstring and extra_repr

* resolved py lint errors

* Added checksums for annotation files

* Minor changes in test

* Updated docstrings, defaults and minor changes in test

* Removed 'os.path.exists' check
Co-authored-by: ABD-01 <myac931@gmai.com>
Co-authored-by: Philip Meier <github.pmeier@posteo.de>
Co-authored-by: Francisco Massa <fvsmassa@gmail.com>