New version with new features.

    - Django version upgrade to 2.1.5
    - Upgrade: required python packages for dev, test, prod etc...
    - Fix: Missing locale generator for JavaScript
    - Fix: Recovery on related model items (undelete admin action).
    - Fix: Wrong translations
    - Add: Hard Delete feature. (*for BaseModelWithSoftDelete usage*)
    - Add: Production logging configuration
    - Add: `noqa` for `__init__` imports