Upgrade bazlets to latest stable-2.14

- Avoid using deprecated depset union

Change-Id: I0f56e2705f20496b970b3aa8e774daa555c1ba34

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index ed3bd17..f31e993 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "2c39029a585bd1d5b785150948f162730f7b7e42",
+    commit = "10cd2e19ba04fcaaf7edef21b8fc407c699fb9d1",
     #local_path = "/home/<user>/projects/bazlets",
 )