[rubygems/rubygems] Add gem env user_gemhome and gem env user_gemdir
gem env user_gemhome
gem env user_gemdir
https://github.com/rubygems/rubygems/commit/14d3f80df6
[rubygems/rubygems] Add
gem env user_gemhomeandgem env user_gemdirhttps://github.com/rubygems/rubygems/commit/14d3f80df6