Upgrade bazlets to latest master to build with 3.1.0-rc3 API

Change-Id: I672d34ecae28eb42629a3bb123d063aa6018c3bb

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index edb3e74..73f832e 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "cf5be217dc024c5e1a001ff24441bef7ac2d90d0",
+    commit = "3c5c68992ede5e2b6722abf4da03b034b57c8e89",
     #local_path = "/home/<user>/projects/bazlets",
 )