kokoro: Don't show bazel progress.
kokoro: Don't show bazel progress.

Fixes #73.

Signed-off-by: Tim 'mithro' Ansell <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@mith.ro>

chipsalliance/verible,chipsalliance/verible,chipsalliance/verible,chipsalliance/verible,chipsalliance/verible