Merge pull request kubernetes#22149 from luxas/onedotsix

Automatic merge from submit-queue

Up to golang 1.6

A second attempt to upgrade go version above `go1.4`
Merge ASAP after you've cut the `release-1.2` branch and feel ready.
`go1.6` should perform slightly better than `go1.5`, so this time it might work
@gmarek @wojtek-t @zmerlynn @mikedanese @brendandburns @ixdy @thockin

development.md

@@ -54,7 +54,7 @@ Kubernetes is written in the [Go](http://golang.org) programming language. If yo
 
 ### Go versions
 
-Requires Go version 1.4.x or 1.5.x
+Requires Go version 1.4.x, 1.5.x or 1.6.x
 
 ## Git setup