@NKV Plesk Onyx release with the features Git/NodeJs/Ruby was announced by Nov 11, 2016. So, there just two months since GA release of Plesk Onyx and one of the months had NY holidays, there is no info about such projects yet. But at least we(Plesk engineering team) use the features for our internal needs.
To learn the features you can study in Plesk University (
http://university.plesk.com/catalog/info/id:192) and/or try it by yourself using trial license (
https://www.plesk.com/download), it has all the required features included.