Update various other go base pkgs to newer alpine (go1.9)

These are those which set $GOPATH but don't use go-compile.sh.

Signed-off-by: Ian Campbell <ijc@docker.com>

test/pkg/ns/Dockerfile

@@ -1,4 +1,4 @@
-FROM linuxkit/alpine:ad35b6ddbc70faa07e59a9d7dee7707c08122e8d AS mirror
+FROM linuxkit/alpine:6211ec0252873c9ff9604101fb256353f5a3832a AS mirror
 RUN mkdir -p /out/etc/apk && cp -r /etc/apk/* /out/etc/apk/
 RUN apk add --no-cache --initdb -p /out \
     alpine-baselayout \