Upgrade bazlets to latest stable-3.0 to build with 3.0.12 API

Change-Id: I510cc1edf91dd7863ecc8986a85ac4b1eb371234

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 69e3814..290b2d1 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "7a9ae377b519934c87184cc05845663ed708b69c",
+    commit = "6d2b8f41ed34dad925b767399d1e4be378abb029",
     #local_path = "/home/<user>/projects/bazlets",
 )