Upgrade bazlets to latest stable-2.14 to build with 2.14.20 API

Change-Id: I1dda61297fe2fc4aa1563f4acc0411ce14cbb88f

WORKSPACE

diff --git a/WORKSPACE b/WORKSPACE
index 4e1d8b6..19aa38f 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "8d7664e169100e537340aed89345c3245cf12f22",
+    commit = "39310fb43f4eaaad2e338b3bcbf393a2f4e11293",
     #local_path = "/home/<user>/projects/bazlets",
 )