Upgrade bazlets to latest stable-3.1 to build with 3.1.2 API

Change-Id: Ieaf8cc0e29524e16485d262c270a0db94d123726
diff --git a/WORKSPACE b/WORKSPACE
index 4b96285..52044db 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "8c8df720486ebe0b60adccd0eceb1c8122edaf58",
+    commit = "4e361c5cd3c33bf2bdccb05ba2aefa3b563d6833",
     #local_path = "/home/<user>/projects/bazlets",
 )