Image augmentation features added

Image augmentation

• The augmentation.py script is now available to automatically generate new images from an existing image folder (see more here)
• Operations like blur, rotation (left, right), flip (vertical, horizontal) and adding random noise are available. More to come soon !
• The class DatasetGenerator make possible to configure its own augmentation pipeline (see more here)

Download image changes

• The dataset_generator.py script for image download from the web is now download.py, the parameters don't change.

Upgrade compatibility to Python 3.6.4

No feature added, this library compatibility is now Python 3.6.

Dataset generator working with Python 2.7.4

This project release is for those who wants to automatically grab images from Bing or Google using Python 2.7.4.