Change effective on 09 July 2015
The first beta of the next version of Go 1.5 beta 1 is now available.
To use the new version specify it in your application’s
... "GoVersion": "go1.5beta1", ...
Go 1.5 is available on the new cedar-14 stack only.
For more details on what’s supported in this beta version of Go, please refer to the Go Support article on Dev Center.