Upgrade bazlets to latest stable-3.0 to build with 3.0.1 API

Change-Id: Id038c5b97dc3bf9af3281812e435e9d92b31849d

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index ddb0e3e..16db61e 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "51049da0140c58ee26f8285bca4393c5e43ce4a1",
+    commit = "f4a0de709185c5447fed6fdce124dc5d33065ca1",
     #local_path = "/home/<user>/projects/bazlets",
 )