luci: buildbucket and milo configurations for linux-xenial-rel try.

Bug: 812051
Change-Id: Ia711acf87123703966d49e7823901ad465027575
Reviewed-on: https://chromium-review.googlesource.com/1060622
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559568}
2 files changed