Add bb tool.

It will probably be useful for people on the infra team.

Change-Id: I20c023901e35ea271eb2c4f4ad363c6e22010404
diff --git a/cipd.ensure b/cipd.ensure
index 695ce23..31e5fc5 100644
--- a/cipd.ensure
+++ b/cipd.ensure
@@ -17,6 +17,9 @@
 # Crimson CLI
 infra/machine-db/crimson/${platform} git_revision:f63aa58d9c396d7e910d8b1ac8ae3d15c0d5be1a
 
+# Buildbucket CLI
+infra/tools/bb/${platform} git_revision:080c945efd74d45e9edac5d5b6cc598bbe106593
+
 # Gerrit CLI
 infra/tools/luci/gerrit/${platform} git_revision:f63aa58d9c396d7e910d8b1ac8ae3d15c0d5be1a