Update DockerHub build hook with golang 1.9 (#998)
Update DockerHub build hook with golang 1.9 (#998)

To align with #992

Signed-off-by: Yong Tang <765086fe2e0c1f980161f127fec596800f327f62@outlook.com>
jremond/coredns,yongtang/coredns,miekg/coredns,ii/coredns,jremond/coredns,johnbelamaric/coredns,coredns/coredns,chrisohaver/coredns,miekg/coredns,johnbelamaric/coredns,ii/coredns