Update bazlets to latest stable-2.15 revision

Change-Id: Ied5d75b472e75fd80379c88feca87c39700ebe9a
diff --git a/WORKSPACE b/WORKSPACE
index bbba776..ae0ab8d 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "1419057b24e41cda9a6ee9d9c431b9005faf8190",
+    commit = "60296e8f7162f279e3885a92014bc69252935612",
     #    local_path = "/home/<user>/projects/bazlets",
 )