Upgrade bazlets to latest stable-2.16 to build with 2.16.7 API

Change-Id: I194198458de896a56f6dc6defa01cfd0d8b78516
diff --git a/WORKSPACE b/WORKSPACE
index eb11a23..2ba668e 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "86562a4c8c2e885aac89eafab34a90571be2ef09",
+    commit = "5c1e201c6835e56a69a980c72206431e2a9d7d80",
     #    local_path = "/Users/dpursehouse/git/bazlets",
 )