Update version info

v0.13.2

v0.13.1

v0.13.0

- Two combination modes: text, HTML
- Introduce Black (code formatting tool)
- Move focus to Python 3.x (prepare to decommission Python 2.7)

v0.12.3

Touch up setup.py

v0.12.2

Add 'Improve Hanaj Library' section in README