how to know dynamically API version?

[Ayellet Lazar]

From my plugin’s code  I need to know dynamically which API version should I use (in order to supports several versions of Go).  

I tried to access to API information according to Go documentation:  

"All APIs SHOULD be accessed from https://go-server-url:8154/go/api. All data SHOULD be sent and received as JSON, specifically application/vnd.go.cd.v1+json. You may access the APIs over plain text, but for security reasons we suggest that you use SSL."

but I dont have an access to this URL:  https://go-server-url:8154/go/api and got 

do you have any idea how to solve it? how to get dynamically the API version?

thanks!!!