Upgrade bazlets to latest stable-2.16 to build with 2.16.6 API

Change-Id: I1d8cdcfc705f8d01edc7d06546bc46ab3b3a6643
diff --git a/WORKSPACE b/WORKSPACE
index c25ab79..6a4b338 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "c2227415d5044f8439bd47edffb0f052f8da2ac5",
+    commit = "f7986f2d3e76ae0ca12a8c43ee91205725bd95e2",
     #local_path = "/home/<user>/projects/bazlets",
 )