OWNERS: Add tonymd@ and tools roller

Change-Id: I3437d5a437470ad338df0079c3cc7a2b3033a9ff
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/62020
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
Reviewed-by: Keir Mierle <keir@google.com>
diff --git a/OWNERS b/OWNERS
index f584bdc..c35fc2a 100644
--- a/OWNERS
+++ b/OWNERS
@@ -6,3 +6,5 @@
 jethier@google.com
 keir@google.com
 mohrr@google.com
+pigweed-roller@pigweed.google.com.iam.gserviceaccount.com
+tonymd@google.com