Milo: Use luci-config for storing buildbot acls

milo/common/config/settings.proto

Index: milo/common/config/settings.proto
diff --git a/milo/common/config/settings.proto b/milo/common/config/settings.proto
new file mode 100644
index 0000000000000000000000000000000000000000..3740ba480335a02feb3bb8a241ce9066346962cc
--- /dev/null
+++ b/milo/common/config/settings.proto
@@ -0,0 +1,14 @@
+// Copyright (c) 2016 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+syntax = "proto3";
+
+package config;
+
+// Settings represents the format for the global (service) config for Milo.
+message Settings{
+  // buildbot_reader is the infra-auth group that is allowed to read internal
+  // buildbot data.
+  string buildbot_internal_reader = 1;

[nodir, 2017/03/20 21:41:32]

presumably we'll have more buildbot-specific settings.
please make a message Buildbot and put internal_reader there.

[hinoka, 2017/03/20 22:19:26]

This seems a little opportunistic, but sure.  Done.

+}