Update bazlets to latest revision on master to use 2.16-SNAPSHOT

- Add optional dir_name argument to gerrit_plugin
- gerrit_plugin: Improve stamping error message
- Set local API version to 2.16-SNAPSHOT

Change-Id: I2c59ccdb0dd6b8ea73f7d3a0ad6d64470a2e966a
diff --git a/WORKSPACE b/WORKSPACE
index 3076a09..b820da4 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -3,7 +3,7 @@
 load("//:bazlets.bzl", "load_bazlets")
 
 load_bazlets(
-    commit = "7ce9a3f58f030635b3a1229b7fb4c62ee7979bc8",
+    commit = "a8bf43a97a2a655752204811d1355b180b082047",
     #local_path = "/home/<user>/projects/bazlets",
 )