Upgrade bazlets to latest stable-3.0 to build with 3.0.2 API

Change-Id: I6cc2026424e020d972ad5c7b8c7efa2d50803ef2

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 1d6ca59..64509ed 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "3c0a1bd325152af99640655831aef109e460bbe7",
+    commit = "631205bc4f7903d3cf656a844cab2bfd6b03f246",
     #local_path = "/home/<user>/projects/bazlets",
 )