Update ruby version 2.2.0 to ruby version 2.3 using github

Hi ,
I am planning to update ruby version that we use from 2.0.0 to be 2.3 in our GitHub repository. Is there a recommended stable commit # in ruby branch "ruby_2_3" that you would recommend me to link to? I need to update the ruby subproject that we have in our GitHub repository to point to a particular commit id?
Which branch on GitHub can be used to get the stable version of ruby 2.3 if it is not in branch "ruby_2_3"?
Which version of rubygem comes with ruby 2.3 by default?
Thanks in advance,-Narine