Update to golang:1.7-alpine3.5 images

Now there is an Alpine 3.5 variant of the Go 1.7 images, use this.

fix #972

Note updated the containers/binfmt image as this will be converted
to go-compile shortly, at which point alpine-build-go can be removed.

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

alpine/base/go-compile/Makefile

@@ -1,6 +1,6 @@
 .PHONY: tag push
 
-BASE=golang:1.7-alpine
+BASE=golang:1.7-alpine3.5
 IMAGE=go-compile
 
 default: push