👽 Decrease minimal version if python to 3.6

🏗️ Attempt to fix CI/CD build on travis-ci.com

✨ Add plantuml mindmap generation support (#30)

* ✨ Add plantuml mindmap support

* Fix import and typing :>

* 🔖 Increment minor version

🔖 Release 0.7.3

🔖 Bump version to 0.7.1

🔖 Bump version to 0.7.0

🔖 Bump version to 0.6.0

🔖 Bump to 0.5.0

🚑 Change deploy condition to valid condition