Milo: Buildbucket PubSub ingestion outline

milo/api/config/settings.proto

Index: milo/api/config/settings.proto
diff --git a/milo/api/config/settings.proto b/milo/api/config/settings.proto
index 9789a4e7787040992b14741084c7f38c0eb1c0bb..af3a14357199132737aafc450f488aaf301c1749 100644
--- a/milo/api/config/settings.proto
+++ b/milo/api/config/settings.proto
@@ -29,6 +29,10 @@ message Settings {
 
     // host is the hostname of the buildbucket instance we're pointing to (sans schema).
     string host = 2;
+
+    // project is the name of the Google Cloud project that the pubsub topic
+    // belongs to.
+    string project = 3;
   }
   Buildbucket buildbucket = 2;