LinearGo now supports Go 1.6
github.com
github.com
https://github.com/danieldk/golinear
These are API-stable and have been used in a couple of projects for some time, including my dependency parser:
https://github.com/danieldk/dpar
Glancing at the API docs, it seems that golinear is definitely more mature/extensive:
https://godoc.org/github.com/danieldk/golinear https://godoc.org/github.com/lazywei/lineargo
There is linearML but sadly the development slowed down once pikatchu got hired by facebook.