Version management and release automation

[OlivierCavadenti]

With a view to improving version management and automate release, I plan to do that tasks:

• Automate published release (for example, when a specific commit is push to master, that will update, generate a clean changelog, tag the version, publish on NPM and post a comment on each released PR). The idea is also to do more releases of small size.
• Add commit naming rules to generate clean changelog (in the previous task): feat/fix/chore/...
• Other rules can be set : automaticaly check if a documentation or tests commit exists.
• Introduce "experimental" or canary version to publish major features for users before introduce them in stable version (for testing purposes).
• Improve PR and dependencies management with Mergify (https://mergify.com/). Need to study this tool if it's not overkill.

Feel free to stop me in my madness if necessary by comment here !