bazel: declare golang 1.9.3
bazel: declare golang 1.9.3

1.9.3 isn't included in the bazel rule for go we are using.

Once the next version of those rules ships, we can likely use the
built-in version.

andrewsykim/kops,kubernetes/kops,justinsb/kops,blakebarnett/kops,tsupertramp/kops,robinpercy/kops,andrewsykim/kops,andrewsykim/kops,aledbf/kops,justinsb/kops,chrislovecnm/kops,chrislovecnm/kops,blakebarnett/kops,andrewsykim/kops,chrislovecnm/kops,robinpercy/kops,kubernetes/kops,chrislovecnm/kops,justinsb/kops,gambol99/kops,tsupertramp/kops,aledbf/kops,blakebarnett/kops,tsupertramp/kops,gambol99/kops,aledbf/kops,robinpercy/kops,mad01/kops,mad01/kops,mad01/kops,blakebarnett/kops,robinpercy/kops,tsupertramp/kops,mad01/kops,gambol99/kops,gambol99/kops,aledbf/kops,kubernetes/kops