Dear Makumba
As far as I know, the master branch is the PRODUCTION version.
There are two other branches were a very very little group of supporters are upgrading the code from using Symfony 2 to using Symfony 3, this will unlock Partkeepr from PHP 7.0/7.1 and allow to use the latest versions of PHP. Even advancing I don't know if this branches are exploitable.
If you have the skills and knowledge and wish to help I guess they will be happy to welcome you.
I'm put my self these day to learn PHP, javascripts and the environment they use expecting to be able to help soon.
I started to program in COBOL and RPG I with punchcards in my early days, learning this can't be harder ... :)
Regards
Daniel